Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 30, 2017
Significant Accounting Policies
Foreign Currency Transactions	Foreign Currency Transactions The Company's foreign subsidiaries are considered to be extensions of the U.S. Company. The functional currency of the foreign subsidiaries is the U.S. dollar. Accordingly, gains and losses resulting from remeasuring transactions denominated in currencies other than U.S. dollars are included in interest income and other, net in the Consolidated Statements of Income.
Use of Estimates	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, stock-based compensation, investments in auction-rate securities, acquired intangible assets, goodwill, long-lived assets and income taxes. Actual results could differ from those estimates, and such differences could be material to the financial statements.
Reclassifications	Reclassifications Certain reclassifications have been made to prior year financial statements to conform to current year presentation.
Fair Value of Financial Instruments	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.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash deposits, certificates of deposit, money market funds and investments in debt securities with original maturities of ninety days or less when purchased.
Investments	Investments The Company's investments typically have original maturities greater than ninety days as of the date of purchase and are classified as either available-for-sale or trading securities. Investments in available-for-sale securities are reported at fair value, with unrealized gains and losses, net of tax, recorded as a component of accumulated other comprehensive income (loss) in the Consolidated Balance Sheet. Investments in trading securities are reported at fair value, with both realized and unrealized gains and losses recorded in interest income and other, net in the Consolidated Statement of Income. Investments in which the Company has the ability and intent, if necessary, to liquidate in order to support its current operations (including those with contractual maturities greater than one year from the date of purchase) are classified as short-term. The Company reviews its available-for-sale investments as of the end of each reporting period for other-than-temporary declines in fair value based on the specific identification method. The Company considers various factors in determining whether an impairment is other-than-temporary, including the severity and duration of the impairment, changes in underlying credit ratings, forecasted recovery, its 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. When the Company concludes that an other-than-temporary impairment has occurred, the Company assesses whether it intends to sell the security or if it is more likely than not that it will be required to sell the security before recovery. If either of these two conditions is met, the Company recognizes a charge in earnings equal to the entire difference between the security's amortized cost basis and its fair value. If the Company does not intend to sell a security and it is not more likely than not that it will be required to sell the security before recovery, the unrealized loss is separated into an amount representing the credit loss, which is recognized in earnings, and the amount related to all other factors, which is recorded in accumulated other comprehensive income (loss). In addition, the Company has made equity investments in non-publicly traded companies that it accounts for using the equity method or cost method. Equity investments in which the Company does not have control, but has the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method. The Company's proportionate share of income or loss is recorded in interest income and other, net in the Consolidated Statement of Income. All other non-marketable equity investments are accounted for using the cost method. The Company periodically reviews these investments for other-than-temporary declines in fair value based on the specific identification method and writes down investments to their fair values when it determines that an other-than-temporary decline has occurred. There were no impairment charges recognized on equity investments during any of the periods presented.
Derivative Financial Instruments	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. The Company uses interest rate swap agreements to manage exposure to interest rate risks. The swap agreements are designated and qualify as cash flow hedges. The effective portion of the gain or loss on the interest rate swaps is recorded in accumulated other comprehensive income (loss) as a separate component of stockholders' equity and is subsequently recognized as interest expense in the Consolidated Statement of Income when the hedged exposure affects earnings. The Company uses foreign currency forward contracts to manage exposure to foreign exchange risk. These instruments are used 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 its foreign currency derivative instruments.
Inventories	Inventories Inventories are stated at the lower of cost, determined using the first-in, first-out method, or net realizable value. The Company writes down the carrying value of inventory to net realizable value for estimated obsolescence or unmarketable inventory based upon assumptions about the age of inventory, future demand and market conditions. Inventory impairment charges establish a new cost basis for inventory and charges are not subsequently reversed to income even if circumstances later suggest that increased carrying amounts are recoverable.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the useful lives of the assets ranging from three to seven years. Leasehold improvements are depreciated over the lease term or their useful life, whichever is shorter. The Company owns the facilities it had previously leased for its headquarters in Austin, Texas. The buildings are located on land which is leased through 2099 from a third party. The rents for these ground leases were prepaid for the term of the leases by the previous lessee. The buildings and leasehold interest in ground leases are being depreciated on a straight-line basis over their estimated useful lives of 40 years and 86 years, respectively.
Business Combinations	Business Combinations The Company records business combinations using the acquisition method of accounting and, accordingly, allocates the fair value of purchase consideration to the assets acquired and liabilities assumed based on their fair values at the acquisition date. The excess of the fair value of purchase consideration over the fair value of the assets acquired and liabilities assumed is recorded as goodwill. The results of operations of the businesses acquired are included in the Company's consolidated results of operations beginning on the date of the acquisition.
Long-Lived Assets	Long-Lived Assets Purchased intangible assets are stated at cost, net of accumulated amortization, and are amortized using the straight-line method over their estimated useful lives, ranging from one to twelve years. Fair values are determined primarily using the income approach, in which the Company projects future expected cash flows and applies an appropriate discount rate. Long-lived assets "held and used" by the Company are reviewed for impairment whenever events or changes in circumstances indicate that their net book value may not be recoverable. When such factors and circumstances exist, the Company compares the projected undiscounted future cash flows associated with the related asset or group of assets over their estimated useful lives against their respective carrying amounts. Impairment, if any, is based on the excess of the carrying amount over the fair value of those assets and is recorded in the period in which the determination was made. The carrying value of goodwill is reviewed at least annually by the Company for possible impairment. The goodwill impairment test is a two-step process. The first step of the impairment analysis compares the fair value of the reporting unit to the net book value of the reporting unit. In determining fair value, several valuation methodologies are allowed, although quoted market prices are the best evidence of fair value. If the results of the first step demonstrate that the net book value is greater than the fair value, the Company must proceed to step two of the analysis. Step two of the analysis compares the implied fair value of goodwill to its carrying amount. If the carrying amount of goodwill exceeds its implied fair value, an impairment loss is recognized equal to that excess. The Company tests goodwill for impairment annually as of the first day of its fourth fiscal quarter and in interim periods if events occur that would indicate that the carrying value of goodwill may be impaired.
Revenue Recognition	Revenue Recognition Revenues are generated predominately by sales of the Company's products. The Company recognizes revenue when all of the following criteria are met: 1) there is persuasive evidence that an arrangement exists, 2) delivery of goods has occurred, 3) the sales price is fixed or determinable, and 4) collectibility is reasonably assured. Generally, revenue from product sales to direct customers and contract manufacturers is recognized upon shipment. A portion of the Company's sales are made to distributors under agreements allowing certain rights of return and price protection related to the final selling price to the end customers. Accordingly, the Company defers revenue and cost of revenue on such sales until the distributors sell the product to the end customers. The net balance of deferred revenue less deferred cost of revenue associated with inventory shipped to a distributor but not yet sold to an end customer is recorded in the deferred income on shipments to distributors liability on the Consolidated Balance Sheet. Such net deferred income balance reflects the Company's estimate of the impact of rights of return and price protection. A small portion of the Company's revenues is derived from the sale of patents. The above revenue recognition criteria for patent sales are generally met upon the execution of the patent sale agreement.
Shipping and Handling	Shipping and Handling Shipping and handling costs are classified as a component of cost of revenues in the Consolidated Statements of Income.
Stock-Based Compensation	Stock-Based Compensation The Company has stock-based compensation plans, which are more fully described in Note 12, Stock-Based Compensation. The Company accounts for those plans using a fair-value method and recognizes the expense in its Consolidated Statement of Income.
Research and Development	Research and Development Research and development costs are expensed as incurred. Research and development expense consists primarily of personnel-related expenses, including stock-based compensation, as well as new product masks, external consulting and services costs, equipment tooling, equipment depreciation, amortization of intangible assets, and an allocated portion of our occupancy costs. Assets purchased to support the Company's ongoing research and development activities are capitalized when related to products which have achieved technological feasibility or have an alternative future use, and are amortized over their estimated useful lives.
Advertising	Advertising Advertising costs are expensed as incurred. Advertising expenses were $1.4 million, $1.6 million and $1.8 million in fiscal 2017, 2016 and 2015, respectively.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method whereby deferred tax asset and liability account balances are determined based on differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax laws and related rates that will be in effect when the differences are expected to reverse. These differences result in deferred tax assets and liabilities, which are included in the Company's Consolidated Balance Sheet. The Company then assesses the likelihood that the deferred tax assets will be realized. A valuation allowance is established against deferred tax assets to the extent the Company believes that it is more likely than not that the deferred tax assets will not be realized, taking into consideration the level of historical taxable income and projections for future taxable income over the periods in which the temporary differences are deductible. Uncertain tax positions must meet a more-likely-than-not threshold to be recognized in the financial statements and the tax benefits recognized are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon final settlement. See Note 16, Income Taxes, for additional information.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (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 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 January 2017, the FASB issued ASU No. 2017-03, Accounting Changes and Error Corrections (Topic 250) and Investments—Equity Method and Joint Ventures (Topic 323). This ASU amends the disclosure requirements for ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), ASU No. 2016-02, Leases (Topic 842) and ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU states that if a registrant does not know or cannot reasonably estimate the impact that the adoption of the above ASUs is expected to have on the financial statements, then in addition to making a statement to that effect, the registrant should consider additional qualitative financial statement disclosures to assist the reader in assessing the significance of the impact that the standard will have on the financial statements of the registrant when adopted. This ASU was effective upon issuance. The Company adopted this ASU and added qualitative financial statement disclosures as deemed necessary. 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 January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. This ASU clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This ASU is effective for annual periods beginning after December 15, 2017, including interim periods within those periods. The impact of the adoption of this ASU on the Company's financial statements will be dependent upon the terms of any future acquisitions or dispositions. In August 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory. This ASU requires the recognition of the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amendments in this ASU should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The Company early adopted this ASU on January 1, 2017. The adoption did not have a material impact on its financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This ASU provides guidance on statement of cash flows presentation for eight specific cash flow issues where diversity in practice exists. This ASU is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company expects 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 (Topic326): 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 March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. This ASU simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The Company adopted this ASU on January 1, 2017. Amendments related to the classification of excess tax benefits on the statement of cash flows were applied prospectively. Prior periods have not been adjusted. In connection with its adoption of ASU 2016-09, the Company has recorded excess tax benefits of $4.3 million during fiscal 2017. The adoption had no other material impact on the Company's 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. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This ASU addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. This ASU is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in Accounting Standards Codification (ASC) 605, Revenue Recognition. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides a five-step process to achieve that core principle. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date, which deferred the effective date of ASU 2014-09 to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. In 2016, the FASB issued the following amendments to ASC 606: ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net), which clarifies the implementation guidance on principal versus agent considerations; ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, which clarifies guidance on identification of performance obligations and licensing implementation; ASU No. 2016-12, Compensation—Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, which provides clarifying guidance on assessing collectibility, presentation of sales taxes, noncash consideration, contract modifications and completed contracts; and ASU No. 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, which clarifies narrow aspects of ASC 606 or corrects unintended application of the guidance. The standard may be applied retrospectively to each prior period presented (full retrospective method) or retrospectively with the cumulative effect recognized as of the date of initial application (modified retrospective method). Under the new standard, the Company expects the timing of revenue recognition from sales to distributors to be accelerated. The Company will recognize revenue at the time of sale to the distributor, net of the impact of estimated price adjustments and rights of return. As a result, revenue recognition is expected to be more directly impacted by shipments to distributors. The Company will adopt this standard using the modified retrospective method. Under this method, incremental disclosures will be provided to present each financial statement line item for fiscal 2018 under the prior standard. The Company is substantially complete with its evaluation of the effect that the adoption will have on its financial statements. In connection with its adoption of ASC 606, the Company expects to record a cumulative-effect adjustment to retained earnings of $26.2 million on December 31, 2017. This adjustment reflects the acceleration of $49.1 million in revenues and $19.7 million in costs of revenues as well as other items.