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Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2018	Jul. 17, 2018
Document and Entity Information
Entity Registrant Name	SILICON LABORATORIES INC
Entity Central Index Key	0001038074
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-29
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		43,351,408
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 194,864	$ 269,366
Short-term investments	347,416	494,657
Accounts receivable, net	93,830	71,367
Inventories	87,163	73,132
Prepaid expenses and other current assets	52,642	39,120
Total current assets	775,915	947,642
Property and equipment, net	132,021	127,682
Goodwill	396,689	288,227
Other intangible assets, net	192,601	83,144
Other assets, net	95,385	88,387
Total assets	1,592,611	1,535,082
Current liabilities:
Accounts payable	40,323	38,851
Deferred revenue and returns liability	24,503
Deferred income on shipments to distributors		50,115
Other current liabilities	74,254	73,359
Total current liabilities	139,080	162,325
Convertible debt	348,233	341,879
Other non-current liabilities	76,830	77,862
Total liabilities	564,143	582,066
Commitments and contingencies
Stockholders' equity:
Preferred stock - $0.0001 par value; 10,000 shares authorized; no shares issued
Common stock - $0.0001 par value; 250,000 shares authorized; 43,350 and 42,707 shares issued and outstanding at June 30, 2018 and December 30, 2017, respectively	4	4
Additional paid-in capital	111,984	102,862
Retained earnings	918,440	851,307
Accumulated other comprehensive loss	(1,960)	(1,157)
Total stockholders' equity	1,028,468	953,016
Total liabilities and stockholders' equity	$ 1,592,611	$ 1,535,082

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Jun. 30, 2018	Dec. 30, 2017
Condensed Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000	250,000
Common stock, shares issued	43,350	42,707
Common stock, shares outstanding	43,350	42,707

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Condensed Consolidated Statements of Income
Revenues	$ 217,106	$ 190,098	$ 422,490	$ 369,126
Cost of revenues	85,814	76,906	166,961	150,773
Gross margin	131,292	113,192	255,529	218,353
Operating expenses:
Research and development	59,495	52,432	114,323	104,756
Selling, general and administrative	53,796	39,826	99,490	79,981
Operating expenses	113,291	92,258	213,813	184,737
Operating income	18,001	20,934	41,716	33,616
Other income (expense):
Interest income and other, net	1,609	1,595	4,811	2,171
Interest expense	(4,888)	(4,699)	(9,771)	(4,501)
Income before income taxes	14,722	17,830	36,756	31,286
Provision (benefit) for income taxes	442	1,261	(3,929)	(709)
Net income	$ 14,280	$ 16,569	$ 40,685	$ 31,995
Earnings per share:
Basic (in dollars per share)	$ 0.33	$ 0.39	$ 0.94	$ 0.76
Diluted (in dollars per share)	$ 0.32	$ 0.38	$ 0.92	$ 0.74
Weighted-average common shares outstanding:
Basic (in shares)	43,312	42,478	43,138	42,287
Diluted (in shares)	44,294	43,178	44,106	43,104

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Condensed Consolidated Statements of Comprehensive Income
Net income	$ 14,280	$ 16,569	$ 40,685	$ 31,995
Net changes to available-for-sale securities:
Unrealized gains (losses) arising during the period	396	163	(363)	408
Reclassification for losses included in net income			49
Net changes to cash flow hedges
Unrealized losses arising during the period	(397)		(420)
Reclassification for (gains) losses included in net income	33		33	(1,808)
Other comprehensive income (loss), before tax	32	163	(701)	(1,400)
Provision (benefit) for income taxes	7	57	(148)	(490)
Other comprehensive income (loss)	25	106	(553)	(910)
Comprehensive income	$ 14,305	$ 16,675	$ 40,132	$ 31,085

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Operating Activities
Net Income	$ 40,685	$ 31,995
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation of property and equipment	7,643	7,308
Amortization of other intangible assets and other assets	18,366	13,571
Amortization of debt discount and debt issuance costs	6,354	3,907
Stock-based compensation expense	24,311	21,652
Deferred income taxes	(5,830)	(6,242)
Changes in operating assets and liabilities:
Accounts receivable	(16,705)	(887)
Inventories	(565)	(7,737)
Prepaid expenses and other assets	(1,759)	12,539
Accounts payable	2,980	2,363
Other current liabilities and income taxes	(17,249)	14
Deferred income, deferred revenue and returns liability	(4,193)	3,251
Other non-current liabilities	(3,260)	(1,169)
Net cash provided by operating activities	50,778	80,565
Investing Activities
Purchases of available-for-sale investments	(148,437)	(389,234)
Sales and maturities of available-for-sale investments	295,405	92,307
Purchases of property and equipment	(11,406)	(8,390)
Purchases of other assets	(5,893)	(1,784)
Acquisitions of business, net of cash acquired	(239,729)	(13,658)
Net cash used in investing activities	(110,060)	(320,759)
Financing Activities
Proceeds from issuance of long-term debt, net		389,468
Payments on debt		(72,500)
Repurchases of common stock	(3,397)
Payment of taxes withheld for vested stock awards	(18,408)	(14,101)
Proceeds from the issuance of common stock	6,585	6,836
Net cash provided by (used in) financing activities	(15,220)	309,703
Increase (decrease) in cash and cash equivalents	(74,502)	69,509
Cash and cash equivalents at beginning of period	269,366	141,106
Cash and cash equivalents at end of period	$ 194,864	$ 210,615

Significant Accounting Policies

6 Months Ended

Jun. 30, 2018

Significant Accounting Policies

Significant Accounting Policies

1. Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The Condensed Consolidated Financial Statements included herein are unaudited; however, they contain all normal recurring accruals and adjustments which, in the opinion of management, are necessary to present fairly the condensed consolidated financial position of Silicon Laboratories Inc. and its subsidiaries (collectively, the “Company”) at June 30, 2018 and December 30, 2017, the condensed consolidated results of its operations for the three and six months ended June 30, 2018 and July 1, 2017, the Condensed Consolidated Statements of Comprehensive Income for the three and six months ended June 30, 2018 and July 1, 2017, and the Condensed Consolidated Statements of Cash Flows for the six months ended June 30, 2018 and July 1, 2017. All intercompany balances and transactions have been eliminated in consolidation. The condensed consolidated results of operations for the three and six months ended June 30, 2018 are not necessarily indicative of the results to be expected for the full year.

The accompanying unaudited Condensed Consolidated Financial Statements do not include certain footnotes and financial presentations normally required under U.S. generally accepted accounting principles (GAAP). Therefore, these Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto for the year ended December 30, 2017, included in the Company’s Form 10-K filed with the Securities and Exchange Commission (SEC) on January 31, 2018.

The Company prepares financial statements on a 52- or 53-week fiscal year that ends on the Saturday closest to December 31. Fiscal 2018 will have 52 weeks and fiscal 2017 had 52 weeks. In a 52-week year, each fiscal quarter consists of 13 weeks.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Among the significant estimates affecting the financial statements are those related to inventories, goodwill, acquired intangible assets, investments in auction-rate securities, other long-lived assets, revenue recognition, stock-based compensation and income taxes. Actual results could differ from those estimates, and such differences could be material to the financial statements.

Reclassifications

Certain reclassifications have been made to prior year financial statements to conform to current year presentation.

Adoption of New Revenue Accounting Standard

The Company adopted Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers, on December 31, 2017, the first day of its fiscal year ending December 29, 2018. The Company elected the modified retrospective method of adoption which only applies to those contracts which were not completed as of December 31, 2017. Prior periods have not been adjusted. In connection with its adoption of ASC 606, the Company recorded a cumulative-effect adjustment to retained earnings of $26.2 million on December 31, 2017. The following reflects the material changes recorded in connection with the cumulative-effect adjustment (in thousands):

Financial Statement Line Item	Increase (Decrease)
Accounts receivable, net	$	230
Prepaid expenses and other current assets	$	7,579
Other assets, net	$	(2,282	)
Deferred revenue and returns liability	$	27,806
Deferred income on shipments to distributors	$	(50,115	)
Other current liabilities	$	1,641
Retained earnings	$	26,195

The following presents the amounts by which financial statement line items were affected in the current period due to the adoption of ASC 606 (in thousands):

Financial Statement Line Item*	Increase (Decrease)
Condensed Consolidated Statements of Income	Three Months Ended June 30, 2018		Six Months Ended June 30, 2018
Revenues	$	7,464	$	8,162
Cost of revenues	$	2,233	$	1,983
Net income	$	4,507	$	4,897

Earnings per share:
Basic	$	0.10	$	0.11
Diluted	$	0.10	$	0.11

Condensed Consolidated Balance Sheet**	June 30, 2018
Prepaid expenses and other current assets	$	2,959
Goodwill	$	(2,842	)
Other assets, net	$	(3,559	)
Deferred revenue and returns liability	$	24,503
Deferred income on shipments to distributors	$	(64,936	)
Other current liabilities	$	5,485
Retained earnings	$	31,092

* Excludes line items that were not materially affected by the Company’s adoption of ASC 606. The adoption had no impact to cash provided by or used in net operating, investing or financing activities in the Condensed Consolidated Statements of Cash Flows.

** Balance sheet line item amounts include the cumulative-effect adjustment recorded on December 31, 2017.

The primary impact of the Company’s adoption of ASC 606 resulted from the acceleration of the timing of revenue recognition on sales to distributors. The Company previously deferred revenue and cost of revenue on such sales until the distributors sold the product to the end customers. The Company now recognizes revenue at the time of sale to the distributor provided all other revenue recognition criteria have been met. The Company records a right of return asset and a returns liability in place of the deferred income on shipments to distributors previously recorded under ASC 605.

Revenue Recognition

Revenue is recognized when control of the promised goods or services is transferred to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services.

Performance Obligations

Substantially all of the Company’s contracts with customers contain a single performance obligation, the sale of mixed-signal integrated circuit (IC) products. Such sales represent a single performance obligation because the sale is one type of good (e.g. an IC) or includes multiple goods that are neither capable of being distinct nor separable from the other promises in the contract (e.g. an IC embedded with software). This performance obligation is satisfied when control of the product is transferred to the customer, which typically occurs upon delivery. Unsatisfied performance obligations primarily represent contracts for products with future delivery dates and with an original expected duration of one year or less. As allowed under ASC 606, the Company has opted to not disclose the amount of unsatisfied performance obligations as these contracts have original expected durations of less than one year.

The Company’s products carry a one-year replacement warranty. The replacement warranty promises customers that delivered products are as specified in the contract (an “assurance-type warranty”). Therefore, the Company accounts for such warranties under ASC 460, Guarantees, and not as a separate performance obligation.

Transaction Price

The transaction price reflects the Company’s expectations about the consideration it will be entitled to receive from the customer and may include fixed or variable amounts. Fixed consideration primarily includes sales to direct customers and sales to distributors in which both the sale to the distributor and the sale to the end customer occur within the same reporting period. Variable consideration includes sales in which the amount of consideration that the Company will receive is unknown as of the end of a reporting period. Such consideration primarily includes sales made to distributors under agreements allowing certain rights of return, referred to as stock rotation, and credits issued to the distributor due to price protection. Stock rotation allows distributors limited levels of returns and is based on the distributor’s prior purchases. Price protection represents price discounts granted to certain distributors and is based on negotiations on sales to end customers.

The Company estimates variable consideration at the most likely amount to which it expects to be entitled. Included in the transaction price estimate are amounts in which it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The estimate is based on information available to the Company, including recent sales activity and pricing data. The Company applies a constraint to its variable consideration estimate which considers both the likelihood of a return and the amount of a potential price concession.

Variable consideration that does not meet revenue recognition criteria is deferred. The Company records a right of return asset in prepaid expenses and other current assets for the costs of distributor inventory not meeting revenue recognition criteria. A corresponding deferred revenue and returns liability amount is recorded for unrecognized revenue associated with such costs.

Contract Balances

Accounts receivable represents the Company’s unconditional right to receive consideration from its customer. Payments are typically due within 30 days of invoicing and do not include a significant financing component. To date, there have been no material impairment losses on accounts receivable. There were no material contract assets or contract liabilities recorded on the Condensed Consolidated Balance Sheet in any of the periods presented.

Recent Accounting Pronouncements

In February 2018, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASU allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The Company early adopted this ASU on December 31, 2017. The adoption did not have a material impact on its financial statements.

In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. The objectives of this ASU are to improve the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and to make certain targeted improvements to simplify the application of the hedge accounting guidance in current GAAP. This ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The Company early adopted this ASU on December 31, 2017. The adoption did not have a material impact on its financial statements.

In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, an entity should recognize an impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value, not to exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. The Company is currently evaluating the effect of the adoption of this ASU, but anticipates that the adoption will not have a material impact on its financial statements.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires instruments measured at amortized cost to be presented at the net amount expected to be collected. Entities are also required to record allowances for available-for-sale debt securities rather than reduce the carrying amount. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its financial statements.

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The core principle of Topic 842 is that a lessee should recognize the assets and liabilities that arise from leases. For operating leases, a lessee is required to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, in the statement of financial position. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the effect that the adoption of this ASU will have on its financial statements. The Company currently expects that most of its operating lease commitments will be subject to the new standard and recognized as right-of-use assets and operating lease liabilities upon the adoption of ASU 2016-02, which will increase the total assets and total liabilities that it reports relative to such amounts prior to adoption.

Earnings Per Share

6 Months Ended

Jun. 30, 2018

Earnings Per Share

Earnings Per Share

2. Earnings Per Share

The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Net income	$	14,280	$	16,569	$	40,685	$	31,995

Shares used in computing basic earnings per share	43,312		42,478		43,138		42,287

Effect of dilutive securities:
Stock-based awards	982		700		968		817
Shares used in computing diluted earnings per share	44,294		43,178		44,106		43,104

Earnings per share:
Basic	$	0.33	$	0.39	$	0.94	$	0.76
Diluted	$	0.32	$	0.38	$	0.92	$	0.74

The Company intends to settle the principal amount of its convertible senior notes in cash and any excess value in shares in the event of a conversion. Accordingly, shares issuable upon conversion of the principal amount have been excluded from the calculation of diluted earnings per share. If the market value of the notes under certain prescribed conditions exceeds the conversion amount, the excess is included in the denominator for the computation of diluted earnings per share using the treasury stock method. As of June 30, 2018, approximately 0.1 million shares were included in the denominator for the calculation of diluted earnings per share. See Note 7, Debt, to the Condensed Consolidated Financial Statements for additional information.

Fair Value of Financial Instruments

6 Months Ended

Jun. 30, 2018

Fair Value of Financial Instruments

Fair Value of Financial Instruments

3. Fair Value of Financial Instruments

The fair values of the Company’s financial instruments are recorded using a hierarchical disclosure framework based upon the level of subjectivity of the inputs used in measuring assets and liabilities. The three levels are described below:

Level 1 - Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2 - Inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

Level 3 - Inputs are unobservable for the asset or liability and are developed based on the best information available in the circumstances, which might include the Company’s own data.

The following summarizes the valuation of the Company’s financial instruments (in thousands). The tables do not include either cash on hand or assets and liabilities that are measured at historical cost or any basis other than fair value.

	Fair Value Measurements at June 30, 2018 Using
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash equivalents:
Money market funds	$	82,111	$	—	$	—	$	82,111
Corporate debt securities	—		23,906		—		23,906
Government debt securities	—		8,359		—		8,359
Total cash equivalents	$	82,111	$	32,265	$	—	$	114,376

Short-term investments:
Government debt securities	$	71,459	$	124,322	$	—	$	195,781
Corporate debt securities	—		151,635		—		151,635
Total short-term investments	$	71,459	$	275,957	$	—	$	347,416

Other assets, net:
Auction rate securities	$	—	$	—	$	5,642	$	5,642
Total	$	—	$	—	$	5,642	$	5,642

Total	$	153,570	$	308,222	$	5,642	$	467,434

	Fair Value Measurements at December 30, 2017 Using
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash equivalents:
Money market funds	$	106,047	$	—	$	—	$	106,047
Corporate debt securities	—		11,231		—		11,231
Government debt securities	53,615		1,453		—		55,068
Total cash equivalents	$	159,662	$	12,684	$	—	$	172,346

Short-term investments:
Government debt securities	$	94,575	$	228,247	$	—	$	322,822
Corporate debt securities	—		171,835		—		171,835
Total short-term investments	$	94,575	$	400,082	$	—	$	494,657

Other assets, net:
Auction rate securities	$	—	$	—	$	5,681	$	5,681
Total	$	—	$	—	$	5,681	$	5,681

Total	$	254,237	$	412,766	$	5,681	$	672,684

Valuation methodology

The Company’s cash equivalents and short-term investments that are classified as Level 2 are valued using non-binding market consensus prices that are corroborated with observable market data; quoted market prices for similar instruments in active markets; or pricing models, such as a discounted cash flow model, with all significant inputs derived from or corroborated with observable market data. Investments classified as Level 3 are valued using a discounted cash flow model. The assumptions used in preparing the discounted cash flow model include estimates for interest rates, amount of cash flows, expected holding periods of the securities and a discount to reflect the Company’s inability to liquidate the securities. The Company’s derivative instruments are valued using discounted cash flow models. The assumptions used in preparing the valuation models include foreign exchange rates, forward and spot prices for currencies, and market observable data of similar instruments.

Available-for-sale investments

The Company’s investments are reported at fair value, with unrealized gains and losses, net of tax, recorded as a component of accumulated other comprehensive loss in the Consolidated Balance Sheet. The following summarizes the contractual underlying maturities of the Company’s available-for-sale investments at June 30, 2018 (in thousands):

	Cost		Fair Value
Due in one year or less	$	313,832	$	313,333
Due after one year through ten years	131,655		130,420
Due after ten years	24,042		23,681
	$	469,529	$	467,434

The available-for-sale investments that were in a continuous unrealized loss position, aggregated by length of time that individual securities have been in a continuous loss position, were as follows (in thousands):

	Less Than 12 Months					12 Months or Greater					Total
As of June 30, 2018	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Government debt securities	$	153,566	$	(893	)	$	3,269	$	(6	)	$	156,835	$	(899	)
Corporate debt securities	126,879		(790		)	11,152		(70		)	138,031		(860		)
Auction rate securities	—		—			5,642		(358		)	5,642		(358		)
	$	280,445	$	(1,683	)	$	20,063	$	(434	)	$	300,508	$	(2,117	)

	Less Than 12 Months					12 Months or Greater					Total
As of December 30, 2017	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Government debt securities	$	244,880	$	(931	)	$	3,027	$	(15	)	$	247,907	$	(946	)
Corporate debt securities	151,149		(447		)	11,578		(73		)	162,727		(520		)
Auction rate securities	—		—			5,681		(319		)	5,681		(319		)
	$	396,029	$	(1,378	)	$	20,286	$	(407	)	$	416,315	$	(1,785	)

The gross unrealized losses as of June 30, 2018 and December 30, 2017 were due primarily to changes in market interest rates and the illiquidity of the Company’s auction-rate securities. The Company’s auction-rate securities have been illiquid since 2008 when auctions for the securities failed because sell orders exceeded buy orders. These securities have a contractual maturity date of 2046. The Company is unable to predict if these funds will become available before their maturity date.

The Company considers the declines in market value of its marketable securities investment portfolio to be temporary in nature. When evaluating an investment for other-than-temporary impairment, the Company reviews factors such as the severity and duration of the impairment, changes in underlying credit ratings, forecasted recovery, the Company’s intent to sell or the likelihood that it would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. As of June 30, 2018, the Company has determined that no other-than-temporary impairment losses existed.

At June 30, 2018 and December 30, 2017, there were no material unrealized gains associated with the Company’s available-for-sale investments.

Level 3 fair value measurements

The following summarizes quantitative information about Level 3 fair value measurements.

Auction rate securities

Fair Value at June 30, 2018 (000s)		Valuation Technique	Unobservable Input	Weighted Average
$	5,642	Discounted cash flow	Estimated yield	2.56%

			Expected holding period	10 years

			Estimated discount rate	3.82%

The Company has followed an established internal control procedure used in valuing auction rate securities. The procedure involves the analysis of valuation techniques and evaluation of unobservable inputs commonly used by market participants to price similar instruments, and which have been demonstrated to provide reasonable estimates of prices obtained in actual market transactions. Outputs from the valuation process are assessed against various market sources when they are available, including marketplace quotes, recent trades of similar illiquid securities, benchmark indices and independent pricing services. The technique and unobservable input parameters may be recalibrated periodically to achieve an appropriate estimation of the fair value of the securities.

Significant changes in any of the unobservable inputs used in the fair value measurement of auction rate securities in isolation could result in a significantly lower or higher fair value measurement. An increase in expected yield would result in a higher fair value measurement, whereas an increase in expected holding period or estimated discount rate would result in a lower fair value measurement. Generally, a change in the assumptions used for expected holding period is accompanied by a directionally similar change in the assumptions used for estimated yield and discount rate.

The following summarizes the activity in Level 3 financial instruments for the three and six months ended June 30, 2018 (in thousands):

Assets

Auction Rate Securities	Three Months Ended		Six Months Ended
Beginning balance	$	5,609	$	5,681
Gain (loss) included in other comprehensive loss	33		(39		)
Balance at June 30, 2018	$	5,642	$	5,642

Fair values of other financial instruments

The Company’s debt is recorded at cost, but is measured at fair value for disclosure purposes. The fair value of the Company’s convertible senior notes is determined using observable market prices. The notes are traded in less active markets and are therefore classified as a Level 2 fair value measurement. As of June 30, 2018 and December 30, 2017, the fair value of the convertible senior notes was $488.7 million and $466.2 million, respectively.

The Company’s other financial instruments, including cash, accounts receivable and accounts payable, are recorded at amounts that approximate their fair values due to their short maturities.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Derivative Financial Instruments

6 Months Ended

Jun. 30, 2018

Derivative Financial Instruments

Derivative Financial Instruments

4. Derivative Financial Instruments

The Company uses derivative financial instruments to manage certain exposures to the variability of interest rates and foreign currency exchange rates. The Company’s objective is to offset increases and decreases in expenses resulting from these exposures with gains and losses on the derivative contracts, thereby reducing volatility of earnings. The Company does not use derivative contracts for speculative or trading purposes. The Company recognizes derivatives, on a gross basis, in the Consolidated Balance Sheet at fair value. Cash flows from derivatives are classified according to the nature of the cash receipt or payment in the Consolidated Statement of Cash Flows.

Cash Flow Hedges

Foreign Currency Forward Contracts

The Company uses foreign currency forward contracts to reduce the earnings impact that exchange rate fluctuations have on operating expenses denominated in currencies other than the U.S. dollar. Changes in the fair value of the contracts are recorded in accumulated other comprehensive loss in the Consolidated Balance Sheet and subsequently reclassified into earnings in the period during which the hedged transaction is recognized. The reclassified amount is reported in the same financial statement line item as the hedged item. If the foreign currency forward contracts are terminated or can no longer qualify as hedging instruments prior to maturity, the fair value of the contracts recorded in accumulated other comprehensive loss may be recognized in the Consolidated Statement of Income based on an assessment of the contracts at the time of termination.

The Company entered into foreign currency forward contracts in March 2018 for a portion of its forecasted operating expenses denominated in the Norwegian Krone. As of June 30, 2018, the contracts had maturities of one to twelve months and an aggregate notional value of $8.4 million. The fair value of the contracts was not material as of June 30, 2018. Contract losses recognized in other comprehensive income during the three and six months ended June 30, 2018 as well as losses expected to be reclassified into earnings in the next 12 months were not material. The amounts reclassified from accumulated other comprehensive loss into earnings were not material for any of the periods presented.

Interest Rate Swaps

The Company entered into an interest rate swap agreement with an original notional value of $72.5 million in connection with its Credit Facility in July 2016. The Company terminated the swap agreement on March 6, 2017, which resulted in the reclassification of $1.8 million of unrealized gains that were previously recorded in accumulated other comprehensive loss into earnings during the three months ended April 1, 2017.

Non-designated Hedges

Foreign Currency Forward Contracts

The Company uses foreign currency forward contracts to reduce the earnings impact that exchange rate fluctuations have on non-U.S. dollar balance sheet exposures. The Company recognizes gains and losses on the foreign currency forward contracts in interest income and other, net in the Consolidated Statement of Income in the same period as the remeasurement loss and gain of the related foreign currency denominated asset or liability. The Company does not apply hedge accounting to these foreign currency forward contracts.

As of June 30, 2018 and July 1, 2017, the Company held one foreign currency forward contract denominated in the Norwegian Krone with a notional value of $1.6 million and $3.6 million, respectively. The fair value of the contracts was not material as of June 30, 2018 or July 1, 2017. The contract held as of June 30, 2018 has a maturity date of September 27, 2018 and it was not designated as a hedging instrument.

The before-tax effect of derivative instruments not designated as hedging instruments was as follows (in thousands):

	Three Months Ended					Six Months Ended
Gain (Loss) Recognized in Income	June 30, 2018		July 1, 2017			June 30, 2018			July 1, 2017			Location
Foreign currency forward contracts	$	114	$	(35	)	$	(9	)	$	(129	)	Interest income and other, net

Balance Sheet Details

6 Months Ended

Jun. 30, 2018

Balance Sheet Details

Balance Sheet Details

5. Balance Sheet Details

The following shows the details of selected Condensed Consolidated Balance Sheet items (in thousands):

Inventories

	June 30, 2018		December 30, 2017
Work in progress	$	57,570	$	46,698
Finished goods	29,593		26,434
	$	87,163	$	73,132

Acquisitions

6 Months Ended

Jun. 30, 2018

Acquisitions

Acquisitions

6. Acquisitions

Z-Wave

On April 18, 2018, the Company completed the acquisition of the Z-Wave business from Sigma Designs, Inc. for $243 million in cash. Z-Wave is an Internet of Things (IoT) technology for smart home solutions.

This strategic acquisition expands the Company’s IoT connectivity portfolio in the connected home market, while further scaling the Company’s engineering team. These factors contributed to a purchase price that was in excess of the fair value of the net assets acquired and, as a result, the Company recorded goodwill. A portion of the goodwill is deductible for tax purposes. The purchase price was allocated as follows (in thousands):

	Amount			Weighted-Average Amortization Period (Years)
Intangible assets:
In-process research and development	$	20,900		Not amortized
Developed technology	69,875			7
Customer relationships	25,000			4
Trademarks	9,900			7
	125,675

Cash and cash equivalents	2,841
Accounts receivable	5,311
Inventory	15,581
Other current assets	329
Goodwill	108,461
Other non-current assets	2,587
Accounts payable	(3,306		)
Other current liabilities	(8,917		)
Other non-current liabilities	(5,993		)
Total purchase price	$	242,569

In-process research and development (IPR&D) represents acquired smart home technology that had not achieved technological feasibility as of the acquisition date. The fair value of IPR&D was determined using the income approach. The discount rate applied to the projected cash flows was 15.0%, which reflects the risks related to the projects. The allocation of the purchase price is preliminary and subject to change, primarily for the valuation of intangible assets and product warranty accruals and the finalization of income tax matters.

Revenues attributable to the Z-Wave business from the date of acquisition to June 30, 2018 were $7.6 million. The Company recorded approximately $4.9 million of acquisition-related costs in selling, general and administrative expenses during the six months ended June 30, 2018.

The following unaudited pro forma financial information presents combined results of operations for each of the periods presented, giving effect to the acquisition as if it had been completed on January 1, 2017. The pro forma financial information includes charges for the fair value write-up associated with acquired inventory, adjustments for amortization expense of acquired intangible assets and tax-related expenses. The pro forma results of operations are presented for informational purposes only and are not necessarily indicative of the results of operations that would have been achieved if the acquisition had taken place on January 1, 2017 or of results that may occur in the future (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Revenues	$	218,145	$	202,697	$	436,333	$	396,911
Net income	$	18,281	$	9,156	$	41,221	$	20,093

Earnings per share:
Basic	$	0.42	$	0.22	$	0.96	$	0.48
Diluted	$	0.41	$	0.21	$	0.93	$	0.47

Debt

6 Months Ended

Jun. 30, 2018

Debt

Debt

7. Debt

1.375% Convertible Senior Notes

On March 6, 2017, the Company completed a private offering of $400 million principal amount convertible senior notes (the “Notes”). The Notes bear interest semi-annually at a rate of 1.375% per year and will mature on March 1, 2022, unless repurchased, redeemed or converted at an earlier date. The Company used $72.5 million of the proceeds to pay off the remaining balance of its Amended Credit Agreement.

The Notes are convertible at an initial conversion rate of 10.7744 shares of common stock per $1,000 principal amount of the Notes, or approximately 4.3 million shares of common stock, which is equivalent to a conversion price of approximately $92.81 per share. The conversion rate is subject to adjustment under certain circumstances. Holders may convert the Notes under the following circumstances: during any calendar quarter after the calendar quarter ended on June 30, 2017 if the closing price of the Company’s common stock for at least 20 trading days in the 30 consecutive trading days ending on the last trading day of the preceding calendar quarter is greater than or equal to 130% of the conversion price of the Notes; during the five business day period after any ten consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the closing sale price of our common stock and the conversion rate on each such trading day; if specified distributions or corporate events occur; if the Notes are called for redemption; or at any time after December 1, 2021. The Company may redeem all or any portion of the Notes, at its option, on or after March 6, 2020, if the last reported sale price of the Company’s common stock has been at least 130% of the conversion price then in effect for at least 20 trading days during any 30 consecutive trading day period. Upon conversion, the Notes may be settled in cash, shares of the Company’s common stock or a combination of cash and shares, at the Company’s election.

The principal balance of the Notes was separated into liability and equity components, and was recorded initially at fair value. The excess of the principal amount of the liability component over its carrying amount represents the debt discount, which is amortized to interest expense over the term of the Notes using the effective interest method. The carrying amount of the liability component was estimated by discounting the contractual cash flows of similar non-convertible debt at an appropriate market rate at the date of issuance.

The Company incurred debt issuance costs of approximately $10.6 million, which was allocated to the liability and equity components in proportion to the allocation of the proceeds. The costs allocated to the liability component are being amortized as interest expense over the term of the Notes using the effective interest method.

The carrying amount of the Notes consisted of the following (in thousands):

	June 30, 2018			December 30, 2017
Liability component
Principal	$	400,000		$	400,000
Unamortized debt discount	(44,979		)	(50,499		)
Unamortized debt issuance costs	(6,788		)	(7,622		)
Net carrying amount	$	348,233		$	341,879

Equity component
Net carrying amount	$	57,735		$	57,735

The liability component of the Notes is recorded in convertible debt on the Consolidated Balance Sheet. The equity component of the Notes is recorded in additional paid-in capital. The effective interest rate for the liability component was 4.75%. As of June 30, 2018, the remaining period over which the debt discount and debt issuance costs will be amortized was 3.7 years.

Interest expense related to the Notes was comprised of the following (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Contractual interest expense	$	1,375	$	1,375	$	2,765	$	1,757
Amortization of debt discount	2,767		2,640		5,520		3,395
Amortization of debt issuance costs	418		398		834		512
	$	4,560	$	4,413	$	9,119	$	5,664

Amended Credit Agreement

On July 31, 2012, the Company and certain of its domestic subsidiaries (the “Guarantors”) entered into a $230 million five-year Credit Agreement (the “Credit Agreement”), which consisted of a $100 million Term Loan Facility and a $130 million Revolving Credit Facility. On July 24, 2015, the Company and the Guarantors amended the Credit Agreement (the “Amended Credit Agreement”) in order to, among other things, increase the borrowing capacity under the Revolving Credit Facility to $300 million (the “Credit Facility”), eliminate the Term Loan Facility and extend the maturity date to five years from the closing date. On July 24, 2015, the Company borrowed $82.5 million under the Amended Credit Agreement and paid off the remaining balance of its Term Loan Facility. In connection with the Company’s offering of the Notes, it entered into a second amendment to the Credit Agreement (the “Second Amended Credit Agreement”) on February 27, 2017 and paid off the remaining balance of $72.5 million.

The Second Amended Credit Agreement retained the key terms and provisions of the first Amended Credit Agreement, including a $25 million letter of credit sublimit and a $10 million swingline loan sublimit. The Company also has an option to increase the size of the borrowing capacity by up to an aggregate of $200 million in additional commitments, subject to certain conditions.

The Revolving Credit Facility, other than swingline loans, will bear interest at the Eurodollar rate plus an applicable margin or, at the option of the Company, a base rate (defined as the highest of the Wells Fargo prime rate, the Federal Funds rate plus 0.50% and the Eurodollar Base Rate plus 1.00%) plus an applicable margin. Swingline loans accrue interest at the base rate plus the applicable margin for base rate loans. The applicable margins for the Eurodollar rate loans range from 1.25% to 2.00% and for base rate loans range from 0.25% to 1.00%, depending in each case, on the leverage ratio as defined in the Agreement.

The Second Amended Credit Agreement contains various conditions, covenants and representations with which the Company must be in compliance in order to borrow funds and to avoid an event of default, including financial covenants that the Company must maintain a leverage ratio (funded debt/EBITDA) of no more than 3.00 to 1 and a minimum fixed charge coverage ratio (EBITDA/interest payments, income taxes and capital expenditures) of no less than 1.25 to 1. As of June 30, 2018, the Company was in compliance with all covenants of the Second Amended Credit Agreement. The Company’s obligations under the Second Amended Credit Agreement are guaranteed by the Guarantors and are secured by a security interest in substantially all assets of the Company and the Guarantors.

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2018
Commitments and Contingencies
Commitments and Contingencies	8. Commitments and Contingencies Securities Litigation On March 15, 2018, a purported class action lawsuit was filed by Ann Noyes on behalf of the stockholders of Sigma Designs, Inc. in the United States District Court in the Northern District of California against Sigma Designs, certain current and former Sigma Designs board members and the Company (collectively, the “Defendants”). The lawsuit alleged violations of Section 14(a) and 20(a) of the Securities Exchange Act of 1934 and SEC Rule 14a-9 arising out of Sigma Designs’ attempt to sell its Z-Wave business to the Company. The lawsuit claimed that the Defendants filed a materially incomplete and misleading preliminary proxy statement in connection with the proposed sale of the Z-Wave business. The lawsuit was voluntarily dismissed on May 17, 2018. Patent Litigation — Cresta Technology On January 28, 2014, Cresta Technology Corporation (“Cresta Technology”), a Delaware corporation, filed a lawsuit against the Company (among others) in the United States District Court in the District of Delaware, alleging infringement of three United States Patents (the “Cresta Patents”). Cresta Technology declared bankruptcy in 2016. The U.S. District Court approved the plaintiff’s voluntary dismissal of the Delaware lawsuit on April 3, 2018. On July 16, 2014, the Company filed a lawsuit against Cresta Technology in the United States District Court in the Northern District of California alleging infringement of six United States Patents. The Northern District of California lawsuit is currently stayed. At this time, the Company cannot predict the outcome of this matter or the resulting financial impact to it, if any. Patent Litigation — Bandspeed On June 21, 2018, Bandspeed, LLC (“Bandspeed”), a Texas limited liability company, filed a lawsuit against the Company in the United States District Court of the Western District of Texas, Austin Division, alleging infringement of eight United States Patents. The Company is reviewing the Bandspeed complaint and intends to defend the matter vigorously. At this time, the Company cannot predict the outcome of the Bandspeed matter or the resulting financial impact to it, if any. Other The Company is involved in various other legal proceedings that have arisen in the normal course of business. While the ultimate results of these matters cannot be predicted with certainty, the Company does not expect them to have a material adverse effect on its Consolidated Financial Statements.

Stockholders' Equity

6 Months Ended

Jun. 30, 2018

Stockholders' Equity

Stockholders' Equity

9. Stockholders’ Equity

Common Stock

The Company issued 0.7 million shares of common stock during the six months ended June 30, 2018.

Share Repurchase Programs

The Board of Directors authorized the following share repurchase programs (in thousands):

Program Authorization Date	Program Termination Date	Program Amount
October 2017	December 2018	$	100,000
January 2017	December 2017	$	100,000

These programs allow for repurchases to be made in the open market or in private transactions, including structured or accelerated transactions, subject to applicable legal requirements and market conditions. The Company repurchased 36 thousand shares of its common stock for $3.4 million during the six months ended June 30, 2018. These shares were retired upon repurchase. The Company did not repurchase any shares of its common stock during the six months ended July 1, 2017.

Reclassifications From Accumulated Other Comprehensive Loss

The following table summarizes the effect on net income from reclassifications out of accumulated other comprehensive loss (in thousands):

	Three Months Ended					Six Months Ended
Reclassification	June 30, 2018			July 1, 2017		June 30, 2018			July 1, 2017
Losses on available-for-sales securities to:
Interest income and other, net	$	—		$	—	$	(49	)	$	—

Gains (losses) on cash flow hedges to:
Interest expense	(33		)	—		(33		)	1,808
	(33		)	—		(82		)	1,808

Income tax expense (benefit)	7			—		17			(633		)

Total reclassifications	$	(26	)	$	—	$	(65	)	$	1,175

Revenues

6 Months Ended

Jun. 30, 2018

Revenues

Revenues

10. Revenues

The Company groups its revenues into four categories, based on the markets and applications in which its products may be used. The following disaggregates the Company’s revenue by product category (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017(1)		June 30, 2018		July 1, 2017(1)
Internet of Things	$	116,023	$	97,727	$	219,114	$	185,575
Infrastructure	51,520		38,221		100,940		74,202
Broadcast	34,172		36,655		70,237		73,982
Access	15,391		17,495		32,199		35,367
Revenues	$	217,106	$	190,098	$	422,490	$	369,126

(1) Under the modified retrospective method, prior period amounts have not been adjusted.

A portion of the Company’s sales are made to distributors under agreements allowing certain rights of return and/or price protection related to the final selling price to the end customers. These factors impact the timing and uncertainty of revenues and cash flows. The Company recognized revenue of $15.4 million and $22.7 million during the three and six months ended June 30, 2018, respectively, from performance obligations that were satisfied in previous reporting periods. The following disaggregates the Company’s revenue by sales channel (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017(1)		June 30, 2018		July 1, 2017(1)
Distributors	$	154,032	$	135,795	$	304,303	$	261,539
Direct customers	63,074		54,303		118,187		107,587
	$	217,106	$	190,098	$	422,490	$	369,126

(1) Under the modified retrospective method, prior period amounts have not been adjusted.

Stock-Based Compensation

6 Months Ended

Jun. 30, 2018

Stock-Based Compensation

Stock-Based Compensation

11. Stock-Based Compensation

In fiscal 2009, the stockholders of the Company approved the 2009 Stock Incentive Plan (the “2009 Plan”) and the 2009 Employee Stock Purchase Plan (the “2009 Purchase Plan”). In fiscal 2017, the stockholders of the Company approved amendments to both the 2009 Plan and the 2009 Purchase Plan. These amendments authorized additional shares of common stock for issuance, to comply with changes in applicable law, improve the Company’s corporate governance and to implement other best practices.

Stock-based compensation costs are based on the fair values on the date of grant for stock awards and stock options and on the date of enrollment for the employee stock purchase plans. The fair values of stock awards (such as restricted stock awards (RSUs), performance stock units (PSUs) and restricted stock awards (RSAs)) are estimated based on their intrinsic values. The fair values of market stock awards (MSUs) are estimated using a Monte Carlo simulation. The fair values of stock options and employee stock purchase plans are estimated using the Black-Scholes option-pricing model.

The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Cost of revenues	$	294	$	264	$	590	$	522
Research and development	5,669		5,503		11,438		10,750
Selling, general and administrative	6,156		5,399		12,283		10,380
	12,119		11,166		24,311		21,652
Income tax benefit	1,677		3,175		6,896		8,457
	$	10,442	$	7,991	$	17,415	$	13,195

The Company had approximately $84.9 million of total unrecognized compensation costs related to granted stock options and awards as of June 30, 2018 that are expected to be recognized over a weighted-average period of approximately 2.2 years. There were no significant stock-based compensation costs capitalized into assets in any of the periods presented.

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2018
Income Taxes
Income Taxes	12. Income Taxes Provision (benefit) for income taxes includes both domestic and foreign income taxes at the applicable tax rates adjusted for non-deductible expenses, research and development tax credits and other permanent differences. Income tax expense (benefit) was $0.4 million and $1.3 million for the three months ended June 30, 2018 and July 1, 2017, resulting in effective tax rates of 3.0% and 7.1%, respectively. Income tax expense (benefit) was $(3.9) million and $(0.7) million for the six months ended June 30, 2018 and July 1, 2017, resulting in effective tax rates of (10.7)% and (2.3)%, respectively. The effective tax rate for the three and six months ended June 30, 2018 decreased from the prior periods primarily due to a decrease in the U.S. statutory tax rate from 35% to 21%. This decrease was partially offset by a decrease in the foreign tax rate benefit. U.S. Tax Reform The Tax Cuts and Jobs Act (the “Act”) was enacted on December 22, 2017. The Act reduces the U.S. federal corporate income tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries previously deferred from tax and creates a new provision designed to tax global intangible low-taxed income (“GILTI”). Also on December 22, 2017, the U.S. Securities and Exchange Commission issued Staff Accounting Bulletin No. 118 (“SAB 118”) which provides for a measurement period of up to one year from the enactment for companies to complete their accounting for the Act. The Company is applying the guidance in SAB 118 when accounting for the enactment-date effects of the Act. At June 30, 2018, the Company has not completed its accounting for the tax effects of the Act but has made reasonable estimates of the effects on the re-measurement of its deferred tax assets and liabilities as well as its transition tax liability. During the three month period ended June 30, 2018, the Company did not record any adjustments to the provisional amounts recorded at December 30, 2017. The Company has not yet fully collected all necessary data to complete its analysis of the effect of the Act on its deferred tax assets and liabilities and is awaiting additional guidance to complete its analysis. Therefore, the Company has not yet completed its accounting of the re-measurement of its deferred tax assets and liabilities. Additionally, the Company has not yet collected and analyzed all necessary tax and earnings data of its foreign operations and therefore, the Company has also not yet completed its accounting for the income tax effects of the transition tax. The Company will continue to make and refine its calculations as additional analysis is completed. In other cases, the Company has not been able to make a reasonable estimate and therefore continues to account for those items based in its existing accounting under ASC 740, Income Taxes, and the provisions of the tax laws that were in effect immediately prior to enactment of the Act. The Act subjects a U.S. shareholder to tax on GILTI earned by certain foreign subsidiaries. Under U.S. GAAP, the Company is permitted to make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. Given the complexity of the GILTI provisions, the Company is still evaluating the effects of the GILTI provisions and has not yet made its accounting policy election. At June 30, 2018, because the Company is still evaluating the GILTI provisions, the Company has included tax expense related to GILTI for the current year in its estimated annual effective tax rate and has not provided additional GILTI on deferred items. Additionally, while the Act has applied a tax on accumulated foreign earnings as of the end of fiscal 2017, the Company is still evaluating whether to continue to apply the exception under ASC 740-30-25-18 to the presumption of repatriation of foreign earnings. As a result, the Company has not provided an estimate of the taxes associated with the reversal of this exception. The Company is analyzing the impact of a change in this presumption but until completing its analysis, the Company continues to apply the exception under ASC 740-30-25-18. Uncertain Tax Positions As of June 30, 2018, the Company had gross unrecognized tax benefits of $2.6 million, of which $2.0 million would affect the effective tax rate if recognized. During the six months ended June 30, 2018, the Company released $1.5 million of unrecognized tax benefits as a result of a lapse in the statute of limitations. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision (benefit) for income taxes. These amounts were not material for any of the periods presented. The Norwegian Tax Administration (“NTA”) has completed its examination of the Company’s Norwegian subsidiary for income tax matters relating to fiscal years 2013, 2014, 2015 and 2016. The Company received a final assessment from the NTA in December 2017 concerning an adjustment to its 2013 taxable income related to the pricing of an intercompany transaction. The adjustment to 2013 taxable income would result in additional Norwegian tax of approximately $30 million, excluding interest and penalties. The Company disagrees with the NTA’s assessment and believes the Company’s position on this matter is more likely than not to be sustained. The Company plans to exhaust all available administrative remedies, and if unable to resolve this matter through administrative remedies with the NTA, the Company plans to pursue judicial remedies. The Company believes that it is likely that the NTA will request a payment of approximately $15 million in 2018 during the appeal process. The Company believes that it has accrued adequate reserves related to all matters contained in tax periods open to examination. Should the Company experience an unfavorable outcome in the NTA matter, however, such an outcome could have a material impact on its financial statements. Tax years 2013 through 2018 remain open to examination by the major taxing jurisdictions to which the Company is subject. The Company is not currently under audit in any major taxing jurisdiction. The Company believes it is reasonably possible that the gross unrecognized tax benefits will decrease by approximately $0.4 million in the next 12 months due to the lapse of the statute of limitations applicable to tax deductions and tax credits claimed on prior year tax returns.

Subsequent Event	6 Months Ended
Subsequent Event	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Event	13. Subsequent Event On July 24, 2018, the U.S. Court of Appeals for the Ninth Circuit reversed the decision of the U.S. Tax Court in Altera Corp. v. Commissioner related to the treatment of stock-based compensation in an intercompany cost-sharing arrangement. The Company is currently evaluating the impact of this decision and such impact could be material to its financial statements.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2018

Significant Accounting Policies

Use of Estimates

Use of Estimates

Reclassifications

Reclassifications

Certain reclassifications have been made to prior year financial statements to conform to current year presentation.

Adoption of New Revenue Accounting Standard

Adoption of New Revenue Accounting Standard

Financial Statement Line Item	Increase (Decrease)
Accounts receivable, net	$	230
Prepaid expenses and other current assets	$	7,579
Other assets, net	$	(2,282	)
Deferred revenue and returns liability	$	27,806
Deferred income on shipments to distributors	$	(50,115	)
Other current liabilities	$	1,641
Retained earnings	$	26,195

The following presents the amounts by which financial statement line items were affected in the current period due to the adoption of ASC 606 (in thousands):

Financial Statement Line Item*	Increase (Decrease)
Condensed Consolidated Statements of Income	Three Months Ended June 30, 2018		Six Months Ended June 30, 2018
Revenues	$	7,464	$	8,162
Cost of revenues	$	2,233	$	1,983
Net income	$	4,507	$	4,897

Earnings per share:
Basic	$	0.10	$	0.11
Diluted	$	0.10	$	0.11

Condensed Consolidated Balance Sheet**	June 30, 2018
Prepaid expenses and other current assets	$	2,959
Goodwill	$	(2,842	)
Other assets, net	$	(3,559	)
Deferred revenue and returns liability	$	24,503
Deferred income on shipments to distributors	$	(64,936	)
Other current liabilities	$	5,485
Retained earnings	$	31,092

** Balance sheet line item amounts include the cumulative-effect adjustment recorded on December 31, 2017.

Revenue Recognition

Revenue Recognition

Performance Obligations

Transaction Price

Contract Balances

Recent Accounting Pronouncements

Recent Accounting Pronouncements

Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2018

Significant Accounting Policies

Schedule of changes recorded in connection with the cumulative-effect adjustment

The following reflects the material changes recorded in connection with the cumulative-effect adjustment (in thousands):

Financial Statement Line Item	Increase (Decrease)
Accounts receivable, net	$	230
Prepaid expenses and other current assets	$	7,579
Other assets, net	$	(2,282	)
Deferred revenue and returns liability	$	27,806
Deferred income on shipments to distributors	$	(50,115	)
Other current liabilities	$	1,641
Retained earnings	$	26,195

Schedule of condensed consolidated statement of income

The following presents the amounts by which financial statement line items were affected in the current period due to the adoption of ASC 606 (in thousands):

Financial Statement Line Item*	Increase (Decrease)
Condensed Consolidated Statements of Income	Three Months Ended June 30, 2018		Six Months Ended June 30, 2018
Revenues	$	7,464	$	8,162
Cost of revenues	$	2,233	$	1,983
Net income	$	4,507	$	4,897

Earnings per share:
Basic	$	0.10	$	0.11
Diluted	$	0.10	$	0.11

Schedule of condensed consolidated balance sheet

The following presents the amounts by which financial statement line items were affected in the current period due to the adoption of ASC 606 (in thousands):

Condensed Consolidated Balance Sheet**	June 30, 2018
Prepaid expenses and other current assets	$	2,959
Goodwill	$	(2,842	)
Other assets, net	$	(3,559	)
Deferred revenue and returns liability	$	24,503
Deferred income on shipments to distributors	$	(64,936	)
Other current liabilities	$	5,485
Retained earnings	$	31,092

** Balance sheet line item amounts include the cumulative-effect adjustment recorded on December 31, 2017.

Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2018

Earnings Per Share

Schedule of computation of basic and diluted earnings per share

The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Net income	$	14,280	$	16,569	$	40,685	$	31,995

Shares used in computing basic earnings per share	43,312		42,478		43,138		42,287

Effect of dilutive securities:
Stock-based awards	982		700		968		817
Shares used in computing diluted earnings per share	44,294		43,178		44,106		43,104

Earnings per share:
Basic	$	0.33	$	0.39	$	0.94	$	0.76
Diluted	$	0.32	$	0.38	$	0.92	$	0.74

Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value of Financial Instruments

Summary of valuation of the financial instruments

	Fair Value Measurements at June 30, 2018 Using
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash equivalents:
Money market funds	$	82,111	$	—	$	—	$	82,111
Corporate debt securities	—		23,906		—		23,906
Government debt securities	—		8,359		—		8,359
Total cash equivalents	$	82,111	$	32,265	$	—	$	114,376

Short-term investments:
Government debt securities	$	71,459	$	124,322	$	—	$	195,781
Corporate debt securities	—		151,635		—		151,635
Total short-term investments	$	71,459	$	275,957	$	—	$	347,416

Other assets, net:
Auction rate securities	$	—	$	—	$	5,642	$	5,642
Total	$	—	$	—	$	5,642	$	5,642

Total	$	153,570	$	308,222	$	5,642	$	467,434

	Fair Value Measurements at December 30, 2017 Using
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash equivalents:
Money market funds	$	106,047	$	—	$	—	$	106,047
Corporate debt securities	—		11,231		—		11,231
Government debt securities	53,615		1,453		—		55,068
Total cash equivalents	$	159,662	$	12,684	$	—	$	172,346

Short-term investments:
Government debt securities	$	94,575	$	228,247	$	—	$	322,822
Corporate debt securities	—		171,835		—		171,835
Total short-term investments	$	94,575	$	400,082	$	—	$	494,657

Other assets, net:
Auction rate securities	$	—	$	—	$	5,681	$	5,681
Total	$	—	$	—	$	5,681	$	5,681

Total	$	254,237	$	412,766	$	5,681	$	672,684

Summarization of contractual underlying maturities of available-for-sale investments

The following summarizes the contractual underlying maturities of the Company’s available-for-sale investments at June 30, 2018 (in thousands):

	Cost		Fair Value
Due in one year or less	$	313,832	$	313,333
Due after one year through ten years	131,655		130,420
Due after ten years	24,042		23,681
	$	469,529	$	467,434

Schedule of available-for-sale investments in continuous unrealized loss position by length of time

	Less Than 12 Months					12 Months or Greater					Total
As of June 30, 2018	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Government debt securities	$	153,566	$	(893	)	$	3,269	$	(6	)	$	156,835	$	(899	)
Corporate debt securities	126,879		(790		)	11,152		(70		)	138,031		(860		)
Auction rate securities	—		—			5,642		(358		)	5,642		(358		)
	$	280,445	$	(1,683	)	$	20,063	$	(434	)	$	300,508	$	(2,117	)

	Less Than 12 Months					12 Months or Greater					Total
As of December 30, 2017	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Government debt securities	$	244,880	$	(931	)	$	3,027	$	(15	)	$	247,907	$	(946	)
Corporate debt securities	151,149		(447		)	11,578		(73		)	162,727		(520		)
Auction rate securities	—		—			5,681		(319		)	5,681		(319		)
	$	396,029	$	(1,378	)	$	20,286	$	(407	)	$	416,315	$	(1,785	)

Summary of quantitative information about level 3 fair value measurements

Auction rate securities

Fair Value at June 30, 2018 (000s)		Valuation Technique	Unobservable Input	Weighted Average
$	5,642	Discounted cash flow	Estimated yield	2.56%

			Expected holding period	10 years

			Estimated discount rate	3.82%

Summary of activity in Level 3 financial instruments

The following summarizes the activity in Level 3 financial instruments for the three and six months ended June 30, 2018 (in thousands):

Assets

Auction Rate Securities	Three Months Ended		Six Months Ended
Beginning balance	$	5,609	$	5,681
Gain (loss) included in other comprehensive loss	33		(39		)
Balance at June 30, 2018	$	5,642	$	5,642

Derivative Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2018

Derivative Financial Instruments

Schedule of before-tax effect of derivative instruments not designated as hedging instruments

The before-tax effect of derivative instruments not designated as hedging instruments was as follows (in thousands):

	Three Months Ended					Six Months Ended
Gain (Loss) Recognized in Income	June 30, 2018		July 1, 2017			June 30, 2018			July 1, 2017			Location
Foreign currency forward contracts	$	114	$	(35	)	$	(9	)	$	(129	)	Interest income and other, net

Balance Sheet Details (Tables)

6 Months Ended

Jun. 30, 2018

Balance Sheet Details

Schedule of condensed consolidated balance sheet details of inventories

The following shows the details of selected Condensed Consolidated Balance Sheet items (in thousands):

Inventories

	June 30, 2018		December 30, 2017
Work in progress	$	57,570	$	46,698
Finished goods	29,593		26,434
	$	87,163	$	73,132

Acquisitions (Tables)

6 Months Ended

Jun. 30, 2018

Acquisitions

Schedule of purchase price allocation

A portion of the goodwill is deductible for tax purposes. The purchase price was allocated as follows (in thousands):

	Amount			Weighted-Average Amortization Period (Years)
Intangible assets:
In-process research and development	$	20,900		Not amortized
Developed technology	69,875			7
Customer relationships	25,000			4
Trademarks	9,900			7
	125,675

Cash and cash equivalents	2,841
Accounts receivable	5,311
Inventory	15,581
Other current assets	329
Goodwill	108,461
Other non-current assets	2,587
Accounts payable	(3,306		)
Other current liabilities	(8,917		)
Other non-current liabilities	(5,993		)
Total purchase price	$	242,569

Schedule of pro forma results of operations

The pro forma results of operations are presented for informational purposes only and are not necessarily indicative of the results of operations that would have been achieved if the acquisition had taken place on January 1, 2017 or of results that may occur in the future (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Revenues	$	218,145	$	202,697	$	436,333	$	396,911
Net income	$	18,281	$	9,156	$	41,221	$	20,093

Earnings per share:
Basic	$	0.42	$	0.22	$	0.96	$	0.48
Diluted	$	0.41	$	0.21	$	0.93	$	0.47

Debt (Tables)

6 Months Ended

Jun. 30, 2018

Debt

Summary of information about the equity and liability components of the convertible senior notes

The carrying amount of the Notes consisted of the following (in thousands):

	June 30, 2018			December 30, 2017
Liability component
Principal	$	400,000		$	400,000
Unamortized debt discount	(44,979		)	(50,499		)
Unamortized debt issuance costs	(6,788		)	(7,622		)
Net carrying amount	$	348,233		$	341,879

Equity component
Net carrying amount	$	57,735		$	57,735

Schedule of components of interest expense

Interest expense related to the Notes was comprised of the following (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Contractual interest expense	$	1,375	$	1,375	$	2,765	$	1,757
Amortization of debt discount	2,767		2,640		5,520		3,395
Amortization of debt issuance costs	418		398		834		512
	$	4,560	$	4,413	$	9,119	$	5,664

Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2018

Stockholders' Equity

Schedule of share repurchase programs

The Board of Directors authorized the following share repurchase programs (in thousands):

Program Authorization Date	Program Termination Date	Program Amount
October 2017	December 2018	$	100,000
January 2017	December 2017	$	100,000

Schedule of reclassifications out of accumulated other comprehensive income (loss)

The following table summarizes the effect on net income from reclassifications out of accumulated other comprehensive loss (in thousands):

	Three Months Ended					Six Months Ended
Reclassification	June 30, 2018			July 1, 2017		June 30, 2018			July 1, 2017
Losses on available-for-sales securities to:
Interest income and other, net	$	—		$	—	$	(49	)	$	—

Gains (losses) on cash flow hedges to:
Interest expense	(33		)	—		(33		)	1,808
	(33		)	—		(82		)	1,808

Income tax expense (benefit)	7			—		17			(633		)

Total reclassifications	$	(26	)	$	—	$	(65	)	$	1,175

Revenues (Tables)

6 Months Ended

Jun. 30, 2018

Revenues

Schedule of disaggregation of revenue by product category

The following disaggregates the Company’s revenue by product category (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017(1)		June 30, 2018		July 1, 2017(1)
Internet of Things	$	116,023	$	97,727	$	219,114	$	185,575
Infrastructure	51,520		38,221		100,940		74,202
Broadcast	34,172		36,655		70,237		73,982
Access	15,391		17,495		32,199		35,367
Revenues	$	217,106	$	190,098	$	422,490	$	369,126

(1) Under the modified retrospective method, prior period amounts have not been adjusted.

Schedule of disaggregation of revenue by sales channel

The following disaggregates the Company’s revenue by sales channel (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017(1)		June 30, 2018		July 1, 2017(1)
Distributors	$	154,032	$	135,795	$	304,303	$	261,539
Direct customers	63,074		54,303		118,187		107,587
	$	217,106	$	190,098	$	422,490	$	369,126

(1) Under the modified retrospective method, prior period amounts have not been adjusted.

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

Stock-Based Compensation

Schedule of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income

The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Cost of revenues	$	294	$	264	$	590	$	522
Research and development	5,669		5,503		11,438		10,750
Selling, general and administrative	6,156		5,399		12,283		10,380
	12,119		11,166		24,311		21,652
Income tax benefit	1,677		3,175		6,896		8,457
	$	10,442	$	7,991	$	17,415	$	13,195

Significant Accounting Policies - Basis of Presentation and Principles of Consolidation (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 30, 2017
Significant Accounting Policies
Length of fiscal year	364 days	364 days
Number of days in each fiscal quarter for 52-week fiscal year	91 days
Low end of range
Significant Accounting Policies
Length of fiscal year	364 days
High end of range
Significant Accounting Policies
Length of fiscal year	371 days

Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 31, 2017	Dec. 30, 2017
Condensed Consolidated Statements of Cash Flows
Accounts receivable, net			$ 16,705	$ 887
Prepaid expenses and other current assets			1,759	(12,539)
Deferred revenue and returns liability			(4,193)	3,251
Condensed Consolidated Statements of Income
Cost of revenues	$ 85,814	$ 76,906	166,961	150,773
Net income	$ 14,280	$ 16,569	$ 40,685	$ 31,995
Earnings per share:
Basic (in dollars per share)	$ 0.33	$ 0.39	$ 0.94	$ 0.76
Diluted (in dollars per share)	$ 0.32	$ 0.38	$ 0.92	$ 0.74
Condensed Consolidated Balance Sheet
Prepaid expenses and other current assets	$ 52,642		$ 52,642			$ 39,120
Goodwill	396,689		396,689			288,227
Other assets, net	95,385		95,385			88,387
Deferred revenue and returns liability	24,503		24,503
Deferred income on shipments to distributors						50,115
Other current liabilities	74,254		74,254			73,359
Retained earnings	918,440		$ 918,440			$ 851,307
Performance Obligations
Product replacement warranty			1 year
ASU 2014-09 - Revenue from Contracts with Customers
Condensed Consolidated Statements of Cash Flows
Accounts receivable, net			$ 230
Prepaid expenses and other current assets			7,579
Other assets, net			(2,282)
Deferred revenue and returns liability			27,806
Deferred income on shipments to distributors			(50,115)
Other current liabilities			1,641
Retained earnings			26,195
Condensed Consolidated Statements of Income
Revenue	7,464		8,162
Cost of revenues	2,233		1,983
Net income	$ 4,507		$ 4,897
Earnings per share:
Basic (in dollars per share)	$ 0.10		$ 0.11
Diluted (in dollars per share)	$ 0.10		$ 0.11
Condensed Consolidated Balance Sheet
Prepaid expenses and other current assets	$ 2,959		$ 2,959
Goodwill	(2,842)		(2,842)
Other assets, net	(3,559)		(3,559)
Deferred revenue and returns liability	24,503		24,503
Deferred income on shipments to distributors	(64,936)		(64,936)
Other current liabilities	5,485		5,485
Retained earnings	$ 31,092		$ 31,092		$ 26,200

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Earnings Per Share
Net income	$ 14,280	$ 16,569	$ 40,685	$ 31,995
Shares used in computing basic earnings per share (in shares)	43,312	42,478	43,138	42,287
Effect of dilutive securities:
Stock-based awards (in shares)	982	700	968	817
Shares used in computing diluted earnings per share (in shares)	44,294	43,178	44,106	43,104
Earnings per share:
Basic (in dollars per share)	$ 0.33	$ 0.39	$ 0.94	$ 0.76
Diluted (in dollars per share)	$ 0.32	$ 0.38	$ 0.92	$ 0.74
Shares issued upon conversion of principal amount
Earnings per share:
Shares excluded from computation of diluted earning per share (in shares)			100

Fair Value of Financial Instruments - Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Financial assets and liabilities measured at fair value on a recurring basis
Total short-term investments	$ 347,416	$ 494,657
Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	82,111	159,662
Total short-term investments	71,459	94,575
Total assets at fair value	153,570	254,237
Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Money market funds
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	82,111	106,047
Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Government debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents		53,615
Total short-term investments	71,459	94,575
Recurring \| Significant Other Observable Inputs (Level 2)
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	32,265	12,684
Total short-term investments	275,957	400,082
Total assets at fair value	308,222	412,766
Recurring \| Significant Other Observable Inputs (Level 2) \| Corporate debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	23,906	11,231
Total short-term investments	151,635	171,835
Recurring \| Significant Other Observable Inputs (Level 2) \| Government debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	8,359	1,453
Total short-term investments	124,322	228,247
Recurring \| Significant Unobservable Inputs (Level 3)
Financial assets and liabilities measured at fair value on a recurring basis
Other assets, net	5,642	5,681
Total assets at fair value	5,642	5,681
Recurring \| Significant Unobservable Inputs (Level 3) \| Auction rate securities
Financial assets and liabilities measured at fair value on a recurring basis
Other assets, net	5,642	5,681
Recurring \| Fair Value
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	114,376	172,346
Total short-term investments	347,416	494,657
Other assets, net	5,642	5,681
Total assets at fair value	467,434	672,684
Recurring \| Fair Value \| Money market funds
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	82,111	106,047
Recurring \| Fair Value \| Corporate debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	23,906	11,231
Total short-term investments	151,635	171,835
Recurring \| Fair Value \| Government debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total cash equivalents	8,359	55,068
Total short-term investments	195,781	322,822
Recurring \| Fair Value \| Auction rate securities
Financial assets and liabilities measured at fair value on a recurring basis
Other assets, net	$ 5,642	$ 5,681

Fair Value of Financial Instruments - Available-for-sale investments (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 30, 2017
Cost
Due in one year or less, Cost	$ 313,832
Due after one year through ten years, Cost	131,655
Due after ten years, Cost	24,042
Total Cost	469,529
Fair Value
Due in one year or less, Fair Value	313,333
Due after one year through ten years, Fair Value	130,420
Due after ten years, Fair Value	23,681
Total Fair Value	467,434
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	280,445	$ 396,029
Fair value of available-for-sale securities, continuous loss position for twelve months or greater	20,063	20,286
Total fair value of available-for-sale securities, continuous loss position	300,508	416,315
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(1,683)	(1,378)
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	(434)	(407)
Available-for-sale securities, total gross unrealized losses	(2,117)	(1,785)
Other than temporary impairment losses
Other-than-temporary impairment losses	0
Government debt securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	153,566	244,880
Fair value of available-for-sale securities, continuous loss position for twelve months or greater	3,269	3,027
Total fair value of available-for-sale securities, continuous loss position	156,835	247,907
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(893)	(931)
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	(6)	(15)
Available-for-sale securities, total gross unrealized losses	(899)	(946)
Corporate debt securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	126,879	151,149
Fair value of available-for-sale securities, continuous loss position for twelve months or greater	11,152	11,578
Total fair value of available-for-sale securities, continuous loss position	138,031	162,727
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(790)	(447)
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	(70)	(73)
Available-for-sale securities, total gross unrealized losses	(860)	(520)
Auction rate securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for twelve months or greater	5,642	5,681
Total fair value of available-for-sale securities, continuous loss position	5,642	5,681
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	(358)	(319)
Available-for-sale securities, total gross unrealized losses	$ (358)	$ (319)

Fair Value of Financial Instruments - Auction rate securities and Contingent consideration (Details) - Auction rate securities - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017
Weighted Average \| Discounted cash flow
Quantitative information for Level 3 Fair Value Measurements Assets
Estimated yield (as a percent)	2.56%
Expected holding period	10 years
Estimated discount rate (as a percent)	3.82%
Recurring
Quantitative information for Level 3 Fair Value Measurements Assets
Fair value balance at the end of the period	$ 5,642	$ 5,609	$ 5,681

Fair Value of Financial Instruments - Assets in Level 3 (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Dec. 30, 2017
Recurring \| Significant Unobservable Inputs (Level 3) \| Auction rate securities
Fair value assets reconciliation of changes
Balance at the beginning of the period	$ 5,609	$ 5,681
Gain (loss) included in other comprehensive loss	33	(39)
Balance at the end of the period	5,642	5,642
Convertible Senior Notes
Fair value assets reconciliation of changes
Fair value of debt	$ 488,700	$ 488,700	$ 466,200

Derivative Financial Instruments - Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Apr. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Jul. 31, 2016
Derivatives of Cash Flow Hedges
Reclassification of unrealized gains included in net income	$ (33)		$ (33)	$ 1,808
Cash flow hedges \| Interest rate swaps
Derivatives of Cash Flow Hedges
Original notional value					$ 72,500
Reclassification of unrealized gains included in net income		$ 1,800
Cash flow hedges \| Foreign currency forward contracts
Derivatives of Cash Flow Hedges
Original notional value	$ 8,400		$ 8,400
Low end of range \| Cash flow hedges \| Foreign currency forward contracts
Derivatives of Cash Flow Hedges
Maturity of contracts			1 month
High end of range \| Cash flow hedges \| Foreign currency forward contracts
Derivatives of Cash Flow Hedges
Maturity of contracts			12 months

Derivative Financial Instruments - Non-designated Hedges (Details) - Not designated as hedging instrument - Foreign currency forward contracts $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) contract	Jul. 01, 2017 USD ($) contract	Jun. 30, 2018 USD ($) contract	Jul. 01, 2017 USD ($) contract
Derivative Instruments, Gain (Loss)
Number of foreign currency forward contract held \| contract	1	1	1	1
Original notional value	$ 1,600	$ 3,600	$ 1,600	$ 3,600
Interest income and other, net
Derivative Instruments, Gain (Loss)
Loss Recognized in Income	$ 114	$ (35)	$ (9)	$ (129)

Balance Sheet Details (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Inventories
Work in progress	$ 57,570	$ 46,698
Finished goods	29,593	26,434
Total inventories	$ 87,163	$ 73,132

Acquisitions (Details) - USD ($) $ / shares in Units, $ in Thousands		2 Months Ended	3 Months Ended		6 Months Ended
	Apr. 18, 2018	Jun. 30, 2018	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017
Purchase price allocation
Goodwill		$ 396,689	$ 396,689		$ 396,689		$ 288,227
Revenues			217,106	$ 190,098	422,490	$ 369,126
Pro forma financial information
Revenues			218,145	202,697	436,333	396,911
Net income			$ 18,281	$ 9,156	$ 41,221	$ 20,093
Earnings per share, Basic			$ 0.42	$ 0.22	$ 0.96	$ 0.48
Earnings per share, Diluted			$ 0.41	$ 0.21	$ 0.93	$ 0.47
Z-Wave
Acquisition
Cash consideration	$ 243,000
Purchase price allocation
Intangible assets	125,675
Cash and cash equivalents	2,841
Accounts receivable	5,311
Inventories	15,581
Other current assets	329
Goodwill	108,461
Other non-current assets	2,587
Accounts payable	(3,306)
Other current liabilities	(8,917)
Other non-current liabilities	(5,993)
Total purchase price	$ 242,569
Discount rate applicable to the cash flows (as a percent)	15.00%
Revenues		7,600
Z-Wave \| Selling, general and administrative
Purchase price allocation
Acquisition-related costs		$ 4,900
Z-Wave \| Developed technology
Purchase price allocation
Intangible assets	$ 69,875
Weighted-Average Amortization Period	7 years
Z-Wave \| Customer relationships
Purchase price allocation
Intangible assets	$ 25,000
Weighted-Average Amortization Period	4 years
Z-Wave \| Trademarks
Purchase price allocation
Intangible assets	$ 9,900
Weighted-Average Amortization Period	7 years
Z-Wave \| In-process research and development
Purchase price allocation
Intangible assets	$ 20,900

Debt - Convertible Senior Notes (Details) $ / shares in Units, $ in Thousands, shares in Millions		6 Months Ended
	Mar. 06, 2017 USD ($) item $ / shares shares	Jul. 01, 2017 USD ($)
Debt
Repayments of Lines of Credit		$ 72,500
Amended Credit Agreement \| Credit Agreement
Debt
Repayments of Lines of Credit	$ 72,500
1.375% Convertible Senior Notes
Debt
Principal amount	$ 400,000
Semi-annual interest rate	1.375%
Conversion rate, shares per $1,000 principal	10.7744
Number of shares of common stock \| shares	4.3
Initial conversion price \| $ / shares	$ 92.81
Number of trading days within 30 trading day period \| item	20
Number of consecutive trading days \| item	30
Minimum amount the sales price of the Company's stock exceeds the conversion price (as a percent)	130.00%
Number of consecutive business days after the 10 consecutive trading day period	5 days
Number of consecutive trading days before the five consecutive business days	10 days
Maximum amount the sales price of the Company's stock exceeds the conversion price (as a percent)	98.00%
Debt issuance costs	$ 10,600

Debt - Carrying amount and interest expense of notes (Details) - 1.375% Convertible Senior Notes - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017
Liability component
Principal	$ 400,000		$ 400,000		$ 400,000
Unamortized debt discount	(44,979)		(44,979)		(50,499)
Unamortized debt issuance costs	(6,788)		(6,788)		(7,622)
Net carrying amount	348,233		348,233		341,879
Equity component
Net carrying amount	$ 57,735		$ 57,735		$ 57,735
Effective interest rate	4.75%		4.75%		4.75%
Amortization of debt discount and debt issuance costs			3 years 8 months 12 days
Interest expense related to the Notes
Contractual interest expense	$ 1,375	$ 1,375	$ 2,765	$ 1,757
Amortization of debt discount	2,767	2,640	5,520	3,395
Amortization of debt issuance costs	418	398	834	512
Interest Expense, Total	$ 4,560	$ 4,413	$ 9,119	$ 5,664

Debt - Amended Credit Agreement (Details) $ in Thousands					6 Months Ended
Debt - Amended Credit Agreement (Details) $ in Thousands	Mar. 06, 2017 USD ($)	Feb. 27, 2017 USD ($)	Jul. 24, 2015 USD ($)	Jul. 31, 2012 USD ($)	Jun. 30, 2018	Jul. 01, 2017 USD ($)
Debt
Repayment of credit facility amount						$ 72,500
Credit Agreement
Debt
Maximum borrowing capacity				$ 230,000
Term of debt instrument				5 years
Term Loan Facility
Debt
Maximum borrowing capacity				$ 100,000
Revolving Credit Facility
Debt
Maximum borrowing capacity				$ 130,000
Revolving Credit Facility \| Base Rate \| Low end of range
Debt
Interest rate margin (as a percent)					0.25%
Revolving Credit Facility \| Base Rate \| High end of range
Debt
Interest rate margin (as a percent)					1.00%
Revolving credit facility, other than swingline loans \| Federal Funds
Debt
Interest rate margin (as a percent)					0.50%
Revolving credit facility, other than swingline loans \| Eurodollar Base Rate
Debt
Interest rate margin (as a percent)					1.00%
Revolving credit facility, other than swingline loans \| Eurodollar Base Rate \| Low end of range
Debt
Interest rate margin (as a percent)					1.25%
Revolving credit facility, other than swingline loans \| Eurodollar Base Rate \| High end of range
Debt
Interest rate margin (as a percent)					2.00%
Amended Credit Agreement \| Credit Agreement
Debt
Amount borrowed			$ 82,500
Repayment of credit facility amount	$ 72,500
Amended Credit Agreement \| Revolving Credit Facility
Debt
Maximum borrowing capacity			$ 300,000
Term of debt instrument			5 years
Second Amended Credit Agreement \| Credit Agreement
Debt
Maximum leverage ratio					3.00
Minimum fixed charge coverage ratio					1.25
Second Amended Credit Agreement \| Revolving Credit Facility
Debt
Additional increase in borrowing capacity of the line of credit available at the entity's option		$ 200,000
Second Amended Credit Agreement \| Swingline Loans
Debt
Maximum borrowing capacity		10,000
Second Amended Credit Agreement \| Letter of Credit
Debt
Maximum borrowing capacity		$ 25,000

Commitments and Contingencies (Details) - patent	Jun. 21, 2018	Jul. 16, 2014	Jan. 28, 2014
Cresta Technology
Patent Litigation
Number of patents allegedly infringed		6	3
Bandspeed
Patent Litigation
Number of patents allegedly infringed	8

Stockholders' Equity - Share repurchase programs (Details) - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Oct. 31, 2017	Jan. 31, 2017
Stockholders' Equity
Number of shares of common stock issued	700
Program Amount authorized to repurchase		$ 100,000	$ 100,000
Repurchase of common stock (in shares)	36
Repurchase of common stock	$ 3,400

Stockholders' Equity - Reclassified from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Amounts Reclassified from AOCI
Income (loss) before income taxes	$ 14,722	$ 17,830	$ 36,756	$ 31,286
Provision (benefit) for income taxes	(442)	(1,261)	3,929	709
Net income	14,280	$ 16,569	40,685	31,995
Reclassifications From Accumulated Other Comprehensive Income (Loss)
Amounts Reclassified from AOCI
Income (loss) before income taxes	(33)		(82)	1,808
Provision (benefit) for income taxes	7		17	(633)
Net income	(26)		(65)	1,175
Losses on available-for-sales securities \| Reclassifications From Accumulated Other Comprehensive Income (Loss)
Amounts Reclassified from AOCI
Interest income and other, net			(49)
Gains (losses) on cash flow hedges \| Reclassifications From Accumulated Other Comprehensive Income (Loss)
Amounts Reclassified from AOCI
Interest expense	$ (33)		$ (33)	$ 1,808

Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Revenues (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Revenues
Revenues	$ 217,106	$ 190,098	$ 422,490	$ 369,126
Revenue from performance obligations	15,400		22,700
Distributors
Revenues
Revenues	154,032	135,795	304,303	261,539
Direct customers
Revenues
Revenues	63,074	54,303	118,187	107,587
Internet of Things
Revenues
Revenues	116,023	97,727	219,114	185,575
Infrastructure
Revenues
Revenues	51,520	38,221	100,940	74,202
Broadcast
Revenues
Revenues	34,172	36,655	70,237	73,982
Access
Revenues
Revenues	$ 15,391	$ 17,495	$ 32,199	$ 35,367

Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Stock-Based Compensation (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Stock-based compensation costs
Stock based compensation costs	$ 12,119	$ 11,166	$ 24,311	$ 21,652
Income tax benefit	1,677	3,175	6,896	8,457
Share based compensation costs after tax	10,442	7,991	17,415	13,195
Total unrecognized compensation costs related to awards	84,900		$ 84,900
Weighted-average period of recognition of unrecognized compensation costs			2 years 2 months 12 days
Cost of revenues
Stock-based compensation costs
Stock based compensation costs	294	264	$ 590	522
Research and development
Stock-based compensation costs
Stock based compensation costs	5,669	5,503	11,438	10,750
Selling, general and administrative
Stock-based compensation costs
Stock based compensation costs	$ 6,156	$ 5,399	$ 12,283	$ 10,380

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 29, 2018	Dec. 30, 2017
Income Taxes
Provision (benefit) for income taxes	$ (442)	$ (1,261)	$ 3,929	$ 709
Effective income tax rate (as a percent)	3.00%	7.10%	(10.70%)	(2.30%)
Federal statutory rate (as a percent)			21.00%			35.00%
Gross unrecognized tax benefits	$ 2,600		$ 2,600
Gross unrecognized tax benefits which would affect the effective tax rate if recognized	2,000		2,000
Unrecognized tax benefits as a result of a lapse in the statute of limitations			1,500
Amount of estimated decrease in unrecognized tax benefits	$ 400		400
2013 \| Norwegian
Income Taxes
Adjustments to taxable income excluding interest and penalties			$ 30,000
Forecast \| Norwegian
Income Taxes
Taxes payable during appeal process					$ 15,000