Illumina (ILMN) 10-K 18 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
In Billions, except Share data in Millions, unless otherwise specified	Dec. 28, 2014	Jan. 30, 2015	Jun. 29, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	Illumina Inc
Entity Central Index Key	1110803
Current Fiscal Year End Date	-16
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	28-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		143.8
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$21.20

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$636,154	$711,637
Short-term investments	702,217	453,966
Accounts receivable, net	289,458	238,946
Inventory	191,144	154,099
Deferred tax assets, current portion	40,786	36,076
Prepaid expenses and other current assets	29,844	22,811
Total current assets	1,889,603	1,617,535
Property and equipment, net	265,264	202,666
Goodwill	724,904	723,061
Intangible assets, net	314,500	331,173
Deferred tax assets, long-term portion	49,848	88,480
Other assets	95,521	56,091
Total assets	3,339,640	3,019,006
Current liabilities:
Accounts payable	82,626	73,655
Accrued liabilities	335,276	219,120
Long-term debt, current portion	304,256	29,288
Total current liabilities	722,158	322,063
Long-term debt	986,780	839,305
Long-term legal contingencies		132,933
Other long-term liabilities	167,904	191,221
Commitments and contingencies
Conversion option subject to cash settlement		282
Stockholders' equity:
Preferred stock, $0.01 par value, 10,000 shares authorized; no shares issued and outstanding at December 28, 2014 and December 29, 2013	0	0
Common stock, $0.01 par value, 320,000 shares authorized; 181,332 shares issued and 143,629 outstanding at December 28, 2014; 175,205 shares issued and 127,723 outstanding at December 29, 2013	1,805	1,753
Additional paid-in capital	2,172,940	2,562,705
Accumulated other comprehensive (loss) income	-1,080	1,234
Retained earnings	561,206	207,855
Treasury stock, 37,703 shares and 47,482 shares at cost at December 28, 2014 and December 29, 2013, respectively	-1,272,073	-1,240,345
Total stockholders’ equity	1,462,798	1,533,202
Total liabilities and stockholders’ equity	$3,339,640	$3,019,006

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, except Per Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	320,000	320,000
Common stock, shares issued	181,332	175,205
Common stock, shares outstanding	143,629	127,723
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Treasury stock, shares	37,703	47,482

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Revenue:
Product revenue	$1,619,511	$1,264,656	$1,055,826
Service and other revenue	241,847	156,522	92,690
Total revenue	1,861,358	1,421,178	1,148,516
Cost of revenue:
Cost of product revenue	431,920	407,877	317,283
Cost of service and other revenue	92,355	67,811	43,552
Amortization of acquired intangible assets	39,373	33,603	14,153
Total cost of revenue	563,648	509,291	374,988
Gross profit	1,297,710	911,887	773,528
Operating expense:
Research and development	388,055	276,743	231,025
Selling, general and administrative	466,283	381,040	285,991
Legal contingencies	-74,338	115,369
Headquarter relocation	5,638	2,624	26,328
Acquisition related (gain) expense, net	-2,639	-11,617	2,774
Unsolicited tender offer related expense		13,621	23,136
Restructuring			3,522
Total operating expense	782,999	777,780	572,776
Income from operations	514,711	134,107	200,752
Other income (expense):
Interest income	3,901	4,887	16,208
Interest expense	-41,728	-39,690	-37,779
Cost-method investment related gain, net	4,427	61,357	45,911
Other expense, net	-32,553	-1,347	-2,484
Total other (expense) income, net	-65,953	25,207	21,856
Income before income taxes	448,758	159,314	222,608
Provision for income taxes	-95,407	-34,006	-71,354
Net income	$353,351	$125,308	$151,254
Net income per basic share	$2.61	$1	$1.23
Net income per diluted share	$2.37	$0.90	$1.13
Shares used in calculating basic net income per share	135,553	125,076	122,999
Shares used in calculating diluted net income per share	148,977	139,936	133,693

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$353,351	$125,308	$151,254
Unrealized (loss) gain on available-for-sale securities, net of deferred tax	-2,314	-889	6
Total comprehensive income	$351,037	$124,419	$151,260

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]	Treasury Stock [Member]
In Thousands, unless otherwise specified
Balance at Jan. 01, 2012	$1,075,215	$1,668	$2,249,900	$2,117	($68,707)	($1,109,763)
Balance, shares at Jan. 01, 2012		166,707				-44,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	151,254				151,254
Unrealized (loss) gain on available-for-sale securities, net of deferred tax	6			6
Issuance of common stock, net of repurchases, shares		3,464				-1,875
Issuance of common stock, net of repurchases, value	-28,165	35	55,106			-83,306
Reclassification of conversion option subject to cash settlement	2,565		2,565
Share-based compensation	94,385		94,385
Net incremental tax benefit related to share-based compensation	17,015		17,015
Equity based contingent compensation	6,306		6,306
Issuance of treasury stock, shares						312
Issuance of treasury stock, value			-5,446			5,446
Balance at Dec. 30, 2012	1,318,581	1,703	2,419,831	2,123	82,547	-1,187,623
Balance, shares at Dec. 30, 2012		170,171				-46,228
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	125,308				125,308
Unrealized (loss) gain on available-for-sale securities, net of deferred tax	-889			-889
Issuance of common stock, net of repurchases, shares		5,034				-1,254
Issuance of common stock, net of repurchases, value	45,543	50	98,215			-52,722
Reclassification of conversion option subject to cash settlement	2,338		2,338
Share-based compensation	105,771		105,771
Net incremental tax benefit related to share-based compensation	53,032		53,032
Equity based contingent compensation	8,278		8,278
Fair value of options assumed in acquisition	240		240
Warrant retirement	-125,000		-125,000
Balance at Dec. 29, 2013	1,533,202	1,753	2,562,705	1,234	207,855	-1,240,345
Balance, shares at Dec. 29, 2013		175,205				-47,482
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	353,351
Unrealized (loss) gain on available-for-sale securities, net of deferred tax	-2,314			-2,314
Issuance of common stock, net of repurchases, shares		6,127				-2,696
Issuance of common stock, net of repurchases, value	-150,965	52	96,204			-247,221
Reclassification of conversion option subject to cash settlement	282		282
Share-based compensation	153,189		153,189
Net incremental tax benefit related to share-based compensation	126,477		126,477
Equity based contingent compensation	2,621		2,621
Tax impact from the issuance, repurchase and conversion of convertible notes	-58,354		-58,354
Warrant exercises, shares						12,475
Warrant exercises, value	0		-215,493			215,493
Repurchase of convertible notes, net of issuances	-494,691		-494,691
Balance at Dec. 28, 2014	$1,462,798	$1,805	$2,172,940	($1,080)	$561,206	($1,272,073)
Balance, shares at Dec. 28, 2014		181,332				-37,703

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Cash flows from operating activities:
Net income	$353,351	$125,308	$151,254
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	61,905	50,810	48,249
Amortization of intangible assets	50,669	47,115	17,070
Share-based compensation expense	152,551	105,826	94,324
Accretion of debt discount	38,069	36,237	35,004
Loss on extinguishment of debt	31,360	555
Contingent compensation expense	2,621	8,278	6,306
Incremental tax benefit related to share-based compensation	-126,479	-56,678	-20,783
Deferred income taxes	99,846	-36,663	-21,698
Change in fair value of contingent consideration	-5,356	-18,784	1,975
(Gain) impairment related to discontinued product line	-2,000	25,214	21,438
Change in estimated cease-use loss	5,651	2,624	22,367
Cost-method investment related gain	-4,427	-61,357	-45,911
Gain on litigation settlement	-109,363	0
Other	9,346	4,533	251
Changes in operating assets and liabilities:
Accounts receivable	-50,381	-15,928	-34,441
Inventory	-36,542	6,217	-23,707
Prepaid expenses and other current assets	6,619	1,783	-3,062
Other assets	-36,256	-16,357	-2,903
Accounts payable	-2,106	2,389	15,112
Accrued liabilities	83,902	38,550	24,388
Accrued legal contingencies	-23,570	132,933
Other long-term liabilities	1,861	3,816	6,640
Net cash provided by operating activities	501,271	386,421	291,873
Cash flows from investing activities:
Purchases of available-for-sale securities	-791,252	-364,001	-925,478
Sales of available-for-sale securities	391,655	523,635	498,371
Maturities of available-for-sale securities	150,229	289,197	400,379
Net cash paid for acquisitions	-3,285	-523,501	-83,156
Net (purchases of) sales proceeds from strategic investments	-11,755	95,580	40,881
Purchases of property and equipment	-105,996	-79,215	-68,781
Cash paid for intangible assets	-36,220	-11,344	-12,228
Net cash used in investing activities	-406,624	-69,649	-150,012
Cash flows from financing activities:
Payments on financing obligations	-29,991	-10,852
Payments on acquisition related contingent consideration liability		-3,985	-3,374
Proceeds from issuance of convertible notes	1,132,378
Repurchase of convertible notes	-1,244,721
Incremental tax benefit related to share-based compensation	126,479	56,678	20,783
Common stock repurchases	-237,183	-50,020	-82,522
Taxes paid related to net share settlement of equity awards	-10,038
Payments on retirement of warrants		-125,000
Proceeds from issuance of common stock	96,328	94,460	54,358
Net cash used in financing activities	-166,748	-38,719	-10,755
Effect of exchange rate changes on cash and cash equivalents	-3,382	-397	-103
Net (decrease) increase in cash and cash equivalents	-75,483	277,656	131,003
Cash and cash equivalents at beginning of year	711,637	433,981	302,978
Cash and cash equivalents at end of year	636,154	711,637	433,981
Supplemental cash flow information:
Cash paid for income taxes	17,886	50,086	74,037
Unsettled short-term investments purchase			$9,154

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 28, 2014
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	Organization and Summary of Significant Accounting Policies
	Organization and Business
	Illumina, Inc. is a provider of sequencing- and array-based solutions, which serves customers in a board range of markets, enabling the adoption of genomic solutions in research and clinical settings. The Company’s customers include leading genomic research centers, academic institutions, government laboratories, hospitals, and reference laboratories, as well as pharmaceutical, biotechnology, agrigenomics, commercial molecular diagnostic, and consumer genomics companies.
	Basis of Presentation
	The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles and include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
	Fiscal Year
	The Company’s fiscal year is 52 or 53 weeks ending the Sunday closest to December 31, with quarters of 13 or 14 weeks ending the Sunday closest to March 31, June 30, September 30, and December 31. Each of the years ended December 28, 2014, December 29, 2013, and December 30, 2012 were 52 weeks.
	Use of Estimates
	The preparation of financial statements requires that management make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses, and related disclosures of contingent assets and liabilities. Actual results could differ from those estimates.
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers. The new standard is based on the principle that revenue should be recognized 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. ASU 2014-09 will be effective for the Company beginning in the first quarter of 2017 and allows for a full retrospective or a modified retrospective adoption approach. The Company is currently evaluating the impact of ASU 2014-09 on its consolidated financial statements.
	Segment Information
	Effective December 30, 2013, the Company reorganized and separated the roles of the Chief Executive Officer and the President, with core market and operational functions centralized and reporting to the President, for the primary purpose of achieving scalability in business operations to support the growth in the Company’s strategic markets. Corporate functions and the President report to the CEO. As a result, the Company operates under one operating segment and reports under one reportable segment.
	Concentrations of Risk
	The Company operates in markets that are highly competitive and rapidly changing. Significant technological changes, shifting customer needs, the emergence of competitive products or services with new capabilities, and other factors could negatively impact the Company’s operating results. A portion of the Company’s customers consist of university and research institutions that management believes are, to some degree, directly or indirectly supported by the United States Government. A significant change in current research funding, particularly with respect to the U.S. National Institutes of Health, could have an adverse impact on the Company’s future revenues and results of operations.
	The Company is also subject to risks related to its financial instruments including its cash and cash equivalents, investments, and accounts receivable. Most of the Company’s cash and cash equivalents as of December 28, 2014 were deposited with U.S. financial institutions, either domestically or with their foreign branches. The Company’s investment policy restricts the amount of credit exposure to any one issuer to 5% of the portfolio or 5% of the total issue size outstanding at the time of purchase and to any one industry sector, as defined by Bloomberg classifications, to 30% of the portfolio at the time of purchase. There is no limit to the percentage of the portfolio that may be maintained in debt securities in U.S. government-sponsored entities, U.S. Treasury securities, and money market funds.
	The Company’s products require customized products and components that currently are available from a limited number of sources. The Company sources certain key products and components included in its products from single vendors.
	The Company performs a regular review of customer activity and associated credit risks and does not require collateral or enter into netting arrangements. Shipments to customers outside the United States comprised 49%, 50%, and 51% of the Company’s revenue for the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively. Customers outside the United States represented 48% and 52% of the Company’s gross trade accounts receivable balance as of December 28, 2014 and December 29, 2013, respectively.
	International sales entail a variety of risks, including currency exchange fluctuations, longer payment cycles, and greater difficulty in accounts receivable collection. The Company is also subject to general geopolitical risks, such as political, social and economic instability, and changes in diplomatic and trade relations. The risks of international sales are mitigated in part by the extent to which sales are geographically distributed. The Company has historically not experienced significant credit losses from investments and accounts receivable.
	Fair Value Measurements
	The Company determines the fair value of its assets and liabilities based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. The Company uses a fair value hierarchy with three levels of inputs, of which the first two are considered observable and the last unobservable, to measure fair value:
	•	Level 1 — Quoted prices in active markets for identical assets or liabilities.
	•	Level 2 — Inputs, other than Level 1, that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	•	Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The carrying amounts of financial instruments such as cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable, and accrued liabilities, excluding acquisition related contingent consideration liabilities, approximate the related fair values due to the short-term maturities of these instruments.
	Functional Currency
	The U.S. dollar is the functional currency of the Company’s international operations. The Company remeasures its foreign subsidiaries’ monetary assets and liabilities to the U.S. dollar and records the net gains or losses resulting from remeasurement in other expense, net in the consolidated statements of income.
	Acquisitions
	The Company measures all assets acquired and liabilities assumed, including contingent considerations and all contractual contingencies, at fair value as of the acquisition date. Contingent purchase considerations to be settled in cash are remeasured to estimated fair value at each reporting period with the change in fair value recorded in acquisition related (gain) expense, net, a component of operating expenses. In addition, the Company capitalizes in-process research and development (IPR&D) and either amortizes it over the life of the product upon commercialization, or impairs it if the project is abandoned. Post-acquisition adjustments in deferred tax asset valuation allowances and liabilities for uncertain tax positions are recorded in current period income tax expense.
	Cash Equivalents and Short-Term Investments
	Cash equivalents are comprised of short-term, highly liquid investments with maturities of 90 days or less at the date of purchase.
	Short-term investments consist predominantly of debt securities in U.S. government-sponsored entities, corporate debt securities, and U.S. Treasury securities. Management classifies short-term investments as available-for-sale at the time of purchase and evaluates such classification as of each balance sheet date. All short-term investments are recorded at estimated fair value. Unrealized gains and losses for available-for-sale securities are included in accumulated other comprehensive income, a component of stockholders’ equity. The Company evaluates its investments to assess whether those with unrealized loss positions are other than temporarily impaired. Impairments are considered to be other than temporary if they are related to deterioration in credit risk or if it is likely that the Company will sell the securities before the recovery of their cost basis. Realized gains, losses, and declines in value judged to be other than temporary are determined based on the specific identification method and are reported in other (expense) income, net in the consolidated statements of income.
	Accounts Receivable
	Trade accounts receivable are recorded at the net invoice value and are not interest bearing. The Company considers receivables past due based on the contractual payment terms. The Company reserves specific receivables if collectibility is no longer reasonably assured. The Company also reserves a percentage of its trade receivable balance based on collection history and current economic trends that might impact the level of future credit losses. The Company re-evaluates such reserves on a regular basis and adjusts its reserves as needed. Once a receivable is deemed to be uncollectible, such balance is charged against the reserve.
	Inventory
	Inventory is stated at the lower of cost or market, on a first in, first out basis. Inventory includes raw materials and finished goods that may be used in the research and development process and such items are expensed as consumed or expired. Provisions for slow moving, excess, and obsolete inventories are estimated based on product life cycles, quality issues, historical experience, and usage forecasts.
	Property and Equipment
	Property and equipment are stated at cost, subject to review for impairment, and depreciated over the estimated useful lives of the assets, which generally range from three to seven years, using the straight-line method. Amortization of leasehold improvements is recorded over the shorter of the lease term or the estimated useful life of the related assets. Maintenance and repairs are charged to operations as incurred. When assets are sold, or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts and any gain or loss is included in operating expense.
	In 2013, as a part of the Company’s ongoing effort to upgrade its current information systems, the Company started the implementation of new enterprise resource planning software and applications to manage parts of its business operations. Certain costs incurred in the development of such internal-use software and software applications, including external direct costs of materials and services and applicable compensation costs of employees devoted to specific software development, are capitalized as computer software costs. Costs incurred outside of the application development stage are expensed as incurred.
	Leases
	Leases are reviewed and classified as capital or operating at their inception. The Company records rent expense on a straight-line basis over the term of the lease, which includes the construction build-out period and lease extension periods, if appropriate. The difference between rent payments and straight-line rent expense is recorded as deferred rent in accrued liabilities and other long-term liabilities. Landlord allowances are amortized on a straight-line basis over the lease term as a reduction to rent expense. The Company capitalizes leasehold improvements and amortizes the value over the shorter of the lease term or expected useful lives.
	Headquarter relocation expenses consisted of expenses such as accelerated depreciation expense, impairment of assets, additional rent expense during the transition period in 2012 when both the new and former headquarter facilities were occupied, moving expenses, cease-use losses, and accretion of interest expense on lease exit liability. The Company completed the relocation of its headquarters in 2012 to another facility in San Diego, California and recorded cease-use losses and the corresponding facility exit obligation upon vacating its former headquarters in 2011 and 2012, calculated as the present value of the remaining lease obligation offset by estimated sublease rental receipts during the remaining lease period, adjusted for deferred items and estimated lease incentives. The Company reassesses the facility exit obligation on a quarterly basis and the key assumptions used in the calculation include the amount and timing of estimated sublease rental receipts, and the risk-adjusted discount rate.
	Goodwill, Intangible Assets and Other Long-Lived Assets
	Goodwill, which has an indefinite useful life, represents the excess of cost over fair value of net assets acquired. The change in the carrying value of goodwill during the year ended December 28, 2014 was due to a current year acquisition and adjustments to the purchase price subsequent to the preliminary allocation of purchase price related to prior year acquisitions. Goodwill is reviewed for impairment at least annually during the second quarter, or more frequently if an event occurs indicating the potential for impairment. During its goodwill impairment review, the Company may assess qualitative factors to determine whether it is more likely than not that the fair value of its reporting unit is less than its carrying amount, including goodwill. The qualitative factors include, but are not limited to, macroeconomic conditions, industry and market considerations, and the overall financial performance of the Company. If, after assessing the totality of these qualitative factors, the Company determines that it is not more likely than not that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company proceeds to perform the two-step test for goodwill impairment. The first step involves comparing the estimated fair value of the reporting unit with its carrying value, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, the Company performs the second step of the goodwill impairment test to determine the amount of loss, which involves comparing the implied fair value of the goodwill to the carrying value of the goodwill. The Company may also elect to bypass the qualitative assessment in a period and elect to proceed to perform the first step of the goodwill impairment test. The Company performed its annual assessment for goodwill impairment in the second quarter of 2014, noting no impairment.
	The Company’s identifiable intangible assets are typically comprised of acquired core technologies, licensed technologies, customer relationships, license agreements, and trade names. The cost of identifiable intangible assets with finite lives is generally amortized on a straight-line basis over the assets’ respective estimated useful lives.
	The Company regularly performs reviews to determine if any event has occurred that may indicate its intangible assets with finite useful lives and other long-lived assets are potentially impaired. If indicators of impairment exist, the Company performs an impairment test to assess the recoverability of the affected assets by determining whether the carrying amount of such assets exceeds the undiscounted expected future cash flows. If the affected assets are not recoverable, the Company estimates the fair value of the assets and records an impairment loss if the carrying value of the assets exceeds the fair value. Factors that may indicate potential impairment include a significant decline in the Company’s stock price and market capitalization compared to its net book value, significant changes in the ability of a particular asset to generate positive cash flows the Company’s strategic business objectives, and the pattern of utilization of a particular asset.
	During 2013, the Company decided to discontinue its Eco and NuPCR product lines to better align its product portfolio with its core strategy. As a result, the Company recorded a total impairment charge of $25.2 million in cost of product revenue, $22.9 million of which related to identifiable intangible assets.
	Derivatives
	The Company is exposed to foreign exchange rate risks in the normal course of business. The Company enters into foreign exchange contracts to manage foreign currency risks related to monetary assets and liabilities that are denominated in currencies other than the U.S. dollar. These foreign exchange contracts are carried at fair value in other assets or other liabilities and are not designated as hedging instruments. Changes in the value of the derivatives are recognized in other expense, net, along with the remeasurement gain or loss on the foreign currency denominated assets or liabilities.
	As of December 28, 2014, the Company had foreign exchange forward contracts in place to hedge exposures in the euro, Japanese yen, and Australian dollar. As of December 28, 2014 and December 29, 2013, the total notional amount of outstanding forward contracts in place for foreign currency purchases was $61.0 million and $54.7 million, respectively. Non-designated foreign exchange forward contract related gain was $4.1 million and $3.5 million for the years ended December 28, 2014 and December 29, 2013, respectively, and immaterial for the year ended December 30, 2012.
	Reserve for Product Warranties
	The Company generally provides a one-year warranty on instruments. Additionally, the Company provides a warranty on consumables through the expiration date, which generally ranges from six to twelve months after the manufacture date. At the time revenue is recognized, the Company establishes an accrual for estimated warranty expenses based on historical experience as well as anticipated product performance. The Company periodically reviews its warranty reserve for adequacy and adjusts the warranty accrual, if necessary, based on actual experience and estimated costs to be incurred. Warranty expense is recorded as a component of cost of product revenue.
	Revenue Recognition
	The Company’s revenue is generated primarily from the sale of products and services. Product revenue primarily consists of sales of instruments and consumables used in genetic analysis. Service and other revenue primarily consists of revenue generated from genotyping and sequencing services and instrument service contracts.
	The Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the seller’s price to the buyer is fixed or determinable, and collectibility is reasonably assured. In instances where final acceptance of the product or system is required, revenue is deferred until all the acceptance criteria have been met. The Company occasionally offers discounts on newly introduced products to recent customers or existing products. These promotions sometimes involve the trade-in of existing products in exchange for a discount on new products. Where applicable, the Company defers a portion of revenue on the sales of existing products in recognition of the promotional discounts until the delivery of new products. All revenue is recorded net of discounts and sales taxes collected on behalf of governmental authorities.
	Revenue from product sales is recognized generally upon transfer of title to the customer, provided that no significant obligations remain and collection of the receivable is reasonably assured. Revenue from instrument service contracts is recognized as the services are rendered, typically evenly over the contract term. Revenue from genotyping and sequencing services is recognized when earned, which is generally at the time the genotyping or sequencing analysis data is made available to the customer or agreed upon milestones are reached.
	In order to assess whether the price is fixed or determinable, the Company evaluates whether an arrangement is cancellable or subject to future changes in price, deliverables, or other terms. If it is determined that the price is not fixed or determinable, the Company defers revenue recognition until the price becomes fixed or determinable. The Company assesses collectibility based on a number of factors, including past transaction history with, and the creditworthiness of, the customer. If the Company determines that collection of a payment is not reasonably assured, revenue recognition is deferred until receipt of payment.
	The Company regularly enters into contracts where revenue is derived from multiple deliverables including products or services. These products or services are generally delivered within a short time frame, approximately three to six months, after the contract execution date. Revenue recognition for contracts with multiple deliverables is based on the individual units of accounting determined to exist in the contract. A delivered item is considered a separate unit of accounting when the delivered item has value to the customer on a stand-alone basis. Items are considered to have stand-alone value when they are sold separately by any vendor or when the customer could resell the item on a stand-alone basis.
	For transactions with multiple deliverables, consideration is allocated at the inception of the contract to all deliverables based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence (VSOE) of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence exists, the Company uses its best estimate of the selling price for the deliverable.
	In order to establish VSOE of selling price, the Company must regularly sell the product or service on a standalone basis with a substantial majority priced within a relatively narrow range. VSOE of selling price is usually the midpoint of that range. If there are not a sufficient number of standalone sales and VSOE of selling price cannot be determined, then the Company considers whether third party evidence can be used to establish selling price. Due to the lack of similar products and services sold by other companies within the industry, the Company has rarely established selling price using third-party evidence. If neither VSOE nor third party evidence of selling price exists, the Company determines its best estimate of selling price using average selling prices over a rolling 12-month period coupled with an assessment of current market conditions. If the product or service has no history of sales or if the sales volume is not sufficient, the Company relies upon prices set by the Company’s pricing committee adjusted for applicable discounts. The Company recognizes revenue for delivered elements only when it determines there are no uncertainties regarding customer acceptance.
	In certain markets, the Company sells products and provides services to customers through distributors that specialize in life science products. In most sales through distributors, the product is delivered directly to customers. In cases where the product is delivered to a distributor, revenue recognition is deferred until acceptance is received from the distributor, and/or the end-user, if required by the applicable sales contract. The terms of sales transactions through distributors are consistent with the terms of direct sales to customers. These transactions are accounted for in accordance with the Company’s revenue recognition policy described herein.
	Share-Based Compensation
	The Company incurs share-based compensation expense related to restricted stock, its Employee Stock purchase Plan (ESPP), and stock options.
	Restricted stock units (RSU), restricted stock awards (RSA), and performance stock units (PSU) are all considered restricted stock. The fair value of restricted stock is determined by the closing market price of the Company’s common stock on the date of grant. The Company recognizes share-based compensation expense based on the fair value on a straight-line basis over the requisite service periods of the awards, taking into consideration estimated forfeitures. PSU represents a right to receive a certain number of shares of common stock based on the achievement of corporate performance goals and continued employment during the vesting period. At each reporting period, the Company reassesses the probability of the achievement of such corporate performance goals and any additional expenses resulting from an adjustment in the estimated shares to be released are treated as a cumulative catch-up in the period of adjustment.
The Company uses the Black-Scholes-Merton option-pricing model to estimate the fair value of stock purchases under ESPP and stock options granted. The model assumptions include expected volatility, term, dividends, and the risk-free interest rate. The Company determines the expected volatility by equally weighing the historical and implied volatility of the Company’s common stock. The historical volatility is generally commensurate with the estimated expected term of the Company’s stock awards, adjusted for the impact of unusual fluctuations and other relevant factors. The implied volatility is calculated from the implied market volatility of exchange-traded call options on the Company’s common stock. The expected term of an award is based on historical forfeiture experience, exercise activity, and on the terms and conditions of the stock awards. The expected dividend yield is determined to be 0% given that the Company has never declared or paid cash dividends on its common stock and does not anticipate paying such cash dividends. The risk-free interest rate is based upon U.S. Treasury securities with remaining terms similar to the expected term of the share-based awards.
Shipping and Handling Expenses
Shipping and handling expenses are included in cost of product revenue.
Research and Development
Research and development expenses include personnel expenses, contractor fees, license fees, facilities costs, and utilities. Expenditures relating to research and development are expensed in the period incurred.
Advertising Costs
The Company expenses advertising costs as incurred. Advertising costs were $16.4 million, $14.5 million, and $10.5 million for the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively.
Income Taxes
The provision for income taxes is computed using the asset and liability method, under which deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities, and for the expected future tax benefit to be derived from tax loss and credit carryforwards. Deferred tax assets and liabilities are determined using the enacted tax rates in effect for the years in which those tax assets are expected to be realized. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date.
Deferred tax assets are regularly assessed to determine the likelihood they will be recovered from future taxable income. A valuation allowance is established when the Company believes it is more likely than not the future realization of all or some of a deferred tax asset will not be achieved. In evaluating the ability to recover deferred tax assets within the jurisdiction which they arise the Company considers all available positive and negative evidence. Factors reviewed include the cumulative pre-tax book income for the past three years, scheduled reversals of deferred tax liabilities, history of earnings and reliable forecasting, projections of pre-tax book income over the foreseeable future, and the impact of any feasible and prudent tax planning strategies.
The Company recognizes excess tax benefits associated with share-based compensation to stockholders’ equity only when realized. When assessing whether excess tax benefits relating to share-based compensation have been realized, the Company follows the with-and-without approach excluding any indirect effects of the excess tax deductions. Under this approach, excess tax benefits related to share-based compensation are not deemed to be realized until after the utilization of all other tax benefits available to the Company.
The Company recognizes the impact of a tax position in the financial statements only if that position is more likely than not of being sustained upon examination by taxing authorities, based on the technical merits of the position. Any interest and penalties related to uncertain tax positions will be reflected in income tax expense.
Net Income per Share
Basic net income per share is computed based on the weighted average number of common shares outstanding during the period. Diluted net income per share is computed based on the sum of the weighted average number of common shares and potentially dilutive common shares outstanding during the period.
Potentially dilutive common shares consist of shares issuable under convertible senior notes, equity awards, and warrants. Convertible senior notes have a dilutive impact when the average market price of the Company’s common stock exceeds the applicable conversion price of the respective notes. Potentially dilutive common shares from equity awards and warrants are determined using the average share price for each period under the treasury stock method. In addition, the following amounts are assumed to be used to repurchase shares: proceeds from exercise of equity awards and warrants; the average amount of unrecognized compensation expense for equity awards; and estimated tax benefits that will be recorded in additional paid-in capital when expenses related to equity awards become deductible. In loss periods, basic net loss per share and diluted net loss per share are identical because the otherwise dilutive potential common shares become anti-dilutive and are therefore excluded.
The following table presents the calculation of weighted average shares used to calculate basic and diluted net income per share (in thousands):
	Years Ended
	December 28,			December 29,			December 30,
	2014			2013			2012
Weighted average shares outstanding	135,553			125,076			122,999
Effect of potentially dilutive common shares from:
Convertible senior notes	3,489			1,340			967
Equity awards	4,340			4,404			3,906
Warrants	5,595			9,116			5,821
Weighted average shares used in calculating diluted net income per share	148,977			139,936			133,693
Potentially dilutive shares excluded from calculation due to anti-dilutive effect	124			996			2,556
Accumulated Other Comprehensive Income
Comprehensive income is comprised of net income and other comprehensive income. Accumulated other comprehensive income on the consolidated balance sheets at December 28, 2014 and December 29, 2013 includes accumulated foreign currency translation adjustments and unrealized gains and losses on the Company’s available-for-sale securities.
The components of accumulated other comprehensive income are as follows (in thousands):
	December 28,				December 29,
	2014				2013
Foreign currency translation adjustments	$	1,289			$	1,289
Unrealized loss on available-for-sale securities, net of deferred tax	(2,369		)		(55		)
Total accumulated other comprehensive income	$	(1,080	)		$	1,234

Balance_Sheet_Account_Details

Balance Sheet Account Details	12 Months Ended
	Dec. 28, 2014
Balance Sheet Account Details [Abstract]
Balance Sheet Account Details	Balance Sheet Account Details
	Short-Term Investments
	The following is a summary of short-term investments (in thousands):
		December 28, 2014												December 29, 2013
					Gross			Gross								Gross		Gross
		Amortized			Unrealized			Unrealized			Estimated			Amortized		Unrealized		Unrealized			Estimated
		Cost			Gains			Losses			Fair Value			Cost		Gains		Losses			Fair Value
	Available-for-sale securities:
	Debt securities in government-sponsored entities	$	51,308		$	10		$	(55	)	$	51,263		$	82,226	$	18	$	(101	)	$	82,143
	Corporate debt securities	502,924			46			(2,882		)	500,088			342,034		312		(376		)	341,970
	U.S. Treasury securities	151,255			5			(394		)	150,866			29,795		58		—			29,853
	Total available-for-sale securities	$	705,487		$	61		$	(3,331	)	$	702,217		$	454,055	$	388	$	(477	)	$	453,966
	As of December 28, 2014, the Company had 467 available-for-sale securities in a gross unrealized loss position, all of which had been in such position for less than twelve months. There were no impairments considered other-than-temporary as it is more likely than not the Company will hold the securities until maturity or the recovery of the cost basis.
	The following table shows the estimated fair values and the gross unrealized losses of the Company’s available-for-sale securities that were in an unrealized loss position for less than twelve months as of December 28, 2014 and December 29, 2013, aggregated by investment category (in thousands):
		December 28, 2014						December 29, 2013
		Estimated			Gross			Estimated			Gross
		Fair Value			Unrealized			Fair Value			Unrealized
					Losses						Losses
	Debt securities in government-sponsored entities	$	36,084		$	(55	)	$	73,362		$	(101	)
	Corporate debt securities	428,078			(2,882		)	168,118			(373		)
	U.S. Treasury securities	143,755			(394		)	—			—
	Total	$	607,917		$	(3,331	)	$	241,480		$	(474	)
	Realized gains and losses are determined based on the specific identification method and are reported in interest income.
	Contractual maturities of available-for-sale debt securities as of December 28, 2014 are as follows (in thousands):
		Estimated Fair Value
	Due within one year	$	238,198
	After one but within five years	464,019
	Total	$	702,217
	Cost-Method Investments
	As of December 28, 2014 and December 29, 2013, the aggregate carrying amounts of the Company’s cost-method investments in non-publicly traded companies were $37.2 million and $22.1 million, respectively, included in other assets. The Company’s cost-method investments are assessed for impairment quarterly. The Company determines that it is not practicable to estimate the fair value of its cost-method investments on a regular basis and does not reassess the fair value of cost-method investments if there are no identified events or changes in circumstances that may have a significant adverse effect on the fair value of the investments.
	During the year ended December 28, 2014, the Company recorded a gain of $4.4 million associated with additional proceeds received for a cost-method investment sold in a prior period. During the year ended December 29, 2013, the Company recorded cost-method investment related gains of $61.4 million, of which $55.2 million related to the sale of the Company’s minority interest in Oxford Nanopore Technologies Ltd.
	No impairment losses were recorded during the years ended December 28, 2014 and December 29, 2013. During the year ended December 30, 2012, the Company determined that a cost-method investment was other-than-temporarily impaired and recorded an impairment loss of $2.7 million. This determination was based upon operational performance trends coupled with uncertainty regarding the entity’s ability to obtain additional funding in a required timeframe for the entity to continue operations.
	Accounts Receivable
	Accounts receivable, net consist of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Accounts receivable from product and service sales	$	292,847		$	241,360
	Other receivables	2,070			1,266
	Total accounts receivable, gross	294,917			242,626
	Allowance for doubtful accounts	(5,459		)	(3,680		)
	Total accounts receivable, net	$	289,458		$	238,946
	Inventory
	Inventory consists of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Raw materials	$	70,316		$	57,398
	Work in process	94,102			70,016
	Finished goods	26,726			26,685
	Total inventory	$	191,144		$	154,099
	Property and Equipment
	Property and equipment, net consists of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Leasehold improvements	$	143,597		$	104,571
	Machinery and equipment	192,715			175,340
	Computer hardware and software	86,929			73,544
	Furniture and fixtures	13,669			10,511
	Building	7,670			7,670
	Construction in progress	35,421			8,531
	Total property and equipment, gross	480,001			380,167
	Accumulated depreciation	(214,737		)	(177,501		)
	Total property and equipment, net	$	265,264		$	202,666
	Capital expenditures included accrued expenditures of $14.1 million for the year ended December 28, 2014, which was excluded from the consolidated statements of cash flows. Accrued capital expenditures were immaterial for the years ended December 29, 2013, and December 30, 2012. As of December 28, 2014, $16.5 million of computer software costs were capitalized associated with the Company’s implementation of a new enterprise resource planning software and applications, which are included primarily in construction in progress assets on the consolidated balance sheets. No computer software costs were capitalized as of December 29, 2013.
	Goodwill
Changes to the Company’s goodwill balance during the year ended December 28, 2014 and December 29, 2013 are as follows (in thousands):
	28-Dec-14			29-Dec-13
Balance at beginning of period	$	723,061		$	369,327
Current period acquisition	3,338			353,734
Purchase price allocation adjustments related to prior year acquisitions	(1,495		)	—
Balance at end of period	$	724,904		$	723,061
Accrued Liabilities
Accrued liabilities consist of the following (in thousands):
	December 28,			December 29,
	2014			2013
Accrued compensation expenses	$	112,606		$	82,705
Deferred revenue, current portion	75,294			50,834
Acquisition related contingent consideration liability, current portion	44,124			6,719
Accrued taxes payable	38,942			30,435
Customer deposits	20,274			13,569
Reserve for product warranties	15,616			10,407
Facility exit obligation, current portion	3,837			5,570
Other	24,583			18,881
Total accrued liabilities	$	335,276		$	219,120

Acquisitions

Acquisitions	12 Months Ended
	Dec. 28, 2014
Business Combinations [Abstract]
Acquisitions	Acquisitions
	Acquisitions in 2013
	On February 21, 2013, the Company acquired all of the outstanding capital stock of Verinata Health, Inc., a provider of non-invasive tests for the early identification of fetal chromosomal abnormalities. With this acquisition, the Company strengthened its reproductive health product portfolio by gaining access to Verinata’s verifi non-invasive prenatal test (NIPT) as well as what management believes to be the most comprehensive intellectual property portfolio in the NIPT industry.
	The contractual price for the acquisition was $350.0 million, plus potential cash payments of up to $100.0 million based on the achievement of certain regulatory and revenue milestones. The aggregate purchase price was determined to be $396.3 million, including total cash payment of $339.3 million, $56.2 million in fair value of the contingent milestone payments, $0.2 million in fair value of converted stock options attributed to pre-combination services, and $0.5 million in loss realized on settlement of preexisting relationships. In connection with the transaction, the Company deposited into escrow $30.0 million of consideration otherwise payable to shareholders of Verinata. This amount was included in the aggregate consideration and was released to shareholders of Verinata in September of 2014. As of December 29, 2013, transaction costs of $3.4 million were expensed as incurred in acquisition related (gain) expense, net.
	In conjunction with the acquisition, the Company assumed the Verinata Health, Inc. 2008 Stock Plan and converted, as of the acquisition date, the unvested stock options outstanding under the plan, all of which were in the money, into 0.4 million unvested stock options to purchase Illumina’s common stock, retaining the original vesting schedules. The fair value of all converted options was $18.9 million, $0.2 million of which was attributed to the pre-combination service period and was included in the calculation of purchase price. The remaining fair value is being recognized over the awards’ remaining vesting periods subsequent to the acquisition. The weighted-average acquisition-date fair value of the converted options was determined using the Black-Scholes option pricing model with the following assumptions: (i) market price of $48.36 per share, which was the closing price of Illumina’s common stock on the acquisition date; (ii) weighted average expected term of 2.3 years; (iii) weighted average risk-free interest rate of 0.32%; (iv) weighted average annualized volatility of 42%; and (v) no dividend yield. The weighted average acquisition-date fair value per share of the assumed stock options was $42.63.
	An initial liability of $56.2 million was recorded for an estimate of the acquisition date fair value of the contingent consideration. Any change in the fair value of the contingent milestone consideration subsequent to the acquisition date was and will be recognized in the consolidated statement of income. The fair value of the regulatory milestone payments was measured by the probability-weighted discounted cash flows and the fair value of the revenue milestone payments was measured using a risk-neutral option pricing model, which captures the present value of the expected payment and the probability of reaching the revenue targets. Key assumptions used in the fair value assessments included discount rates ranging from 6% to 20%, volatility of 50%, risk-free rates of 0.26%, revenue projections, and the probability of achieving regulatory milestones. This fair value measurement of the contingent consideration is based on significant inputs not observed in the market and thus represents a Level 3 measurement. Level 3 instruments are valued based on unobservable inputs that are supported by little or no market activity and reflect the Company’s own assumptions in measuring fair value.
	As of December 29, 2013, the allocation of the purchase price to the assets acquired and liabilities assumed on the acquisition date was as follows (in thousands):
		Allocation of purchase price
	Cash and cash equivalents	$	9,151
	Accounts receivable	2,801
	Inventory	1,110
	Prepaid expenses and other current assets	979
	Property and equipment	12,083
	Other assets	978
	Intangible assets	176,490
	Goodwill	227,453
	Accounts payable	(2,539		)
	Accrued liabilities	(3,803		)
	Lease financing obligation	(9,695		)
	Deferred tax liability	(18,741		)
	Total purchase price	$	396,267
	In conjunction with the acquisition, the Company assumed Verinata’s building lease, for which Verinata was considered the accounting owner of the leased building and as such, recorded the fair value of the building as an asset as of the acquisition date. The building is depreciated over a useful life of 30 years. The Company also recorded the related lease financing obligation as a liability assumed, representing the present value of all remaining building lease payments with an interest rate of 6.0%. The annual future minimum payments, including the balloon payment at the end of the lease for the value of the building to be transferred to the landlord, are $1.0 million for each of the years 2015 and 2016, and $8.4 million for 2017.
	The following table summarizes the fair value of identifiable intangible assets acquired (amounts in thousands):
		Weighted Average Useful Lives		Fair Value
		(in years)
	Developed technology	13		$	170,200
	Customer relationships	5		4,690
	Trade name	2		1,600
	Total intangible assets acquired, excluding goodwill			$	176,490
	The fair value of the developed technology and trade name was estimated using an income approach. Under the income approach, an intangible asset’s fair value is equal to the present value of future economic benefits to be derived from ownership of the asset. The estimated fair value was developed by discounting future net cash flows to their present value at market-based rates of return. The fair value of the customer relationships was developed using a cost approach by estimating the time and personnel effort in constructing the customer base. The useful life of the intangible assets for amortization purposes was determined by considering the period of expected cash flows used to measure the fair value of the intangible assets adjusted as appropriate for the entity-specific factors including legal, regulatory, contractual, competitive, economic, or other factors that may limit the useful life of intangible assets.
	The excess of the fair value of the total consideration over the estimated fair value of the net assets was recorded as goodwill, which was primarily attributable to the synergies expected from combining the technologies of Illumina with those of Verinata, including complementary products that will enhance the Company’s overall product portfolio, and the value of the workforce that became our employees following the closing of the acquisitions. The goodwill recognized is not deductible for income tax purposes.
	During 2013, the Company also completed acquisitions of Advanced Liquid Logic Inc., a provider of liquid handling solutions, NextBio, a provider of clinical and genomic informatics tools, and another development-stage company. As a result of these transactions, the Company recorded developed technologies of $79.7 million with a weighted average useful life of eight years and goodwill of $124.8 million.
	Pro Forma Information
	The following unaudited pro forma information presents the consolidated results of operations of the Company as if the acquisitions completed during the year ended December 29, 2013 had occurred at the beginning of the applicable annual reporting period, with pro forma adjustments to give effect to intercompany transactions to be eliminated, amortization of intangible assets, share-based compensation, and transaction costs directly associated with the acquisitions (in thousands, except per share amounts):
		Years Ended
		December 29,				December 30,
		2013				2012
	Net revenues	$	1,433,935			$	1,161,241
	Net income	$	113,869			$	92,645
	Net income per share-basic	$	0.91			$	0.75
	Net income per share-diluted	$	0.81			$	0.69
	These unaudited pro forma consolidated financial results have been prepared for illustrative purposes only and do not purport to be indicative of the results of operations that actually would have resulted had the acquisition occurred on the first day of the earliest period presented, or of the future results of the consolidated entities. The unaudited pro forma consolidated financial information does not reflect any operating efficiencies and cost savings that may be realized from the integration of the acquisition.
	Acquisition in 2012
	On September 19, 2012, the Company announced the acquisition of BlueGnome Ltd. (BlueGnome), a provider of cytogenetics and in vitro fertilization screening products. Total consideration for the acquisition was $95.5 million, which included $88.0 million in initial cash payments and $7.5 million in fair value of contingent cash consideration of up to $20.0 million based on the achievement of certain revenue based milestones by December 28, 2014.
	The Company estimated the fair value of contingent cash consideration using a probability weighted discounted cash flow approach, a Level 3 measurement, using a discount rate of 30%. The Company also agreed to pay up to $20.0 million to BlueGnome shareholders contingent upon the retention of certain key employees and certain other criteria. Such contingent payments are recognized as contingent compensation expense over the retention period through December 28, 2014.
	As a result of this acquisition, the Company recorded developed technologies of $25.0 million, customer relationships of $16.8 million, and a trade name of $7.1 million with average useful lives of seven, five, and ten years, respectively. The Company recorded the excess consideration of approximately $47.5 million as goodwill.
	Summary of Contingent Compensation Expenses
	Contingent compensation expenses recorded as a result of acquisitions consist of the following (in thousands):
		Years Ended
		December 28,				December 29,		December 30,
		2014				2013		2012
	Contingent compensation expense, included in research and development expense	$	1,509			$	544	$	3,419
	Contingent compensation expense, included in selling, general and administrative expense	2,756				13,066		5,732
	Total contingent compensation expense	$	4,265			$	13,610	$	9,151

Intangible_Assets

Intangible Assets	12 Months Ended
	Dec. 28, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible Assets	Intangible Assets
	The Company’s intangible assets, excluding goodwill, include acquired licensed and core technologies, customer relationships, license agreements, and trade name. Amortization for the intangible assets that have finite useful lives is generally recorded on a straight-line basis over their useful lives.
	The following is a summary of the Company’s identifiable intangible assets (in thousands):
		December 28, 2014									December 29, 2013
		Gross				Accumulated			Intangibles,		Gross		Accumulated			Intangibles,
		Carrying				Amortization			Net		Carrying		Amortization			Net
		Amount									Amount
	Licensed technologies	$	83,956			$	(39,423	)	$	44,533	$	48,361	$	(31,927	)	$	16,434
	Core technologies	321,200				(77,493		)	243,707		321,700		(45,534		)	276,166
	Customer relationships	26,461				(12,522		)	13,939		26,770		(7,376		)	19,394
	License agreements	15,042				(4,592		)	10,450		18,917		(4,947		)	13,970
	Trade name	4,700				(2,829		)	1,871		11,800		(6,591		)	5,209
	Total intangible assets, net	$	451,359			$	(136,859	)	$	314,500	$	427,548	$	(96,375	)	$	331,173
	As of December 28, 2014, the remaining weighted-average amortization period for identifiable intangible assets was 8.1 years.
	Intangible assets acquired during the year ended December 28, 2014 are as follows (in thousands):
		Weighted-Average		Gross
		Useful Lives		Carrying
		(in years)		Amount
	Licensed technologies	4.7		$	35,595
	Customer relationships	0.5		291
	License agreements	7.2		125
	Total intangible asset additions			$	36,011
	The estimated annual amortization of intangible assets for the next five years and thereafter is shown in the following table (in thousands). Actual amortization expense to be reported in future periods could differ from these estimates as a result of acquisitions, divestitures, asset impairments, among other factors.
		Estimated Annual Amortization
	2015	$	52,994
	2016	47,752
	2017	43,276
	2018	33,971
	2019	30,685
	Thereafter	105,822
	Total	$	314,500

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 28, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	The following table presents the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of December 28, 2014 and December 29, 2013 (in thousands):
		December 28, 2014									December 29, 2013
		Level 1			Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Assets:
	Money market funds (cash equivalent)	$	431,172		$	—	$	—	$	431,172	$	478,755	$	—	$	—	$	478,755
	Debt securities in government-sponsored entities	—			51,263		—		51,263		—		82,143		—		82,143
	Corporate debt securities	—			500,088		—		500,088		—		341,970		—		341,970
	U.S. Treasury securities	150,866			—		—		150,866		29,853		—		—		29,853
	Deferred compensation plan assets	—			23,486		—		23,486		—		17,805		—		17,805
	Total assets measured at fair value	$	582,038		$	574,837	$	—	$	1,156,875	$	508,608	$	441,918	$	—	$	950,526
	Liabilities:
	Acquisition related contingent consideration liabilities	$	—		$	—	$	44,124	$	44,124	$	—	$	—	$	49,480	$	49,480
	Deferred compensation liability	—			20,310		—		20,310		—		14,957		—		14,957
	Total liabilities measured at fair value	$	—		$	20,310	$	44,124	$	64,434	$	—	$	14,957	$	49,480	$	64,437
	The Company holds available-for-sale securities that consist of highly liquid, investment grade debt securities. The Company considers information provided by the Company’s investment accounting and reporting service provider in the measurement of fair value of its debt securities. The investment service provider provides valuation information from an industry-recognized valuation service. Such valuations may be based on trade prices in active markets for identical assets or liabilities (Level 1 inputs) or valuation models using inputs that are observable either directly or indirectly (Level 2 inputs), such as quoted prices for similar assets or liabilities, yield curve, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, broker and dealer quotes, as well as other relevant economic measures. The Company’s deferred compensation plan assets consist primarily of investments in life insurance contracts carried at cash surrender value, which reflects the net asset value of the underlying publicly traded mutual funds. The Company performs control procedures to corroborate the fair value of its holdings, including comparing valuations obtained from its investment service provider to valuations reported by the Company’s asset custodians, validation of pricing sources and models, and review of key model inputs if necessary.
	The Company reassesses the fair value of contingent consideration to be settled in cash related to acquisitions on a quarterly basis using the income approach. This is a Level 3 measurement. Significant assumptions used in the measurement include probabilities of achieving the remaining milestones and the discount rates, which depend on the milestone risk profiles. The changes in fair value of the contingent considerations during the years ended December 28, 2014, December 29, 2013, and December 30, 2012 were due to changes in the estimated payments and a shorter discounting period.
	Changes in estimated fair value of contingent consideration liabilities from January 1, 2012 through December 28, 2014 are as follows (in thousands):
		Contingent
		Consideration
		Liability
		(Level 3
		Measurement)
	Balance as of January 1, 2012	$	6,638
	Acquisition of BlueGnome	7,500
	Change in estimated fair value, recorded in acquisition related (gain) expense, net	1,975
	Cash payments	(3,594		)
	Balance as of December 30, 2012	12,519
	Additional liability recorded for current period acquisitions	60,184
	Change in estimated fair value, recorded in acquisition related (gain) expense, net	(18,784		)
	Cash payments	(4,439		)
	Balance as of December 29, 2013	49,480
	Change in estimated fair value, recorded in acquisition related (gain) expense, net	(5,356		)
	Balance as of December 28, 2014	$	44,124

Convertible_Senior_Notes

Convertible Senior Notes	12 Months Ended
	Dec. 28, 2014
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes
	As of December 28, 2014, the Company had outstanding $320.0 million in principal amount of 0.25% convertible senior notes due March 15, 2016, $632.5 million in principal amount of 0% convertible senior notes due June 15, 2019, and $517.5 million in principal amount of 0.5% convertible senior notes due June 15, 2021.
	0% Convertible Senior Notes due 2019 and 0.5% Convertible Senior Notes due 2021
	On June 11, 2014, the Company issued $632.5 million aggregate principal amount of 0% convertible senior notes due 2019 (2019 Notes) and $517.5 million aggregate principal amount of 0.5% convertible senior notes due 2021 (2021 Notes) in an offering conducted in accordance with Rule 144A under the Securities Act of 1933, as amended. The Notes were issued at 100% of par value. The net proceeds from the issuance, after deducting the offering expenses payable by the Company, was $1,132.4 million. The Company used the net proceeds plus cash on hand to repurchase a portion of the outstanding 2016 Notes in privately negotiated transactions concurrently with the issuance of the 2019 and 2021 Notes.
	Both the 2019 and 2021 Notes will be convertible into cash, shares of common stock, or a combination of cash and shares of common stock, at the Company's election, based on an initial conversion rate, subject to adjustment, of 3.9318 shares per $1,000 principal amount of the notes (which represents an initial conversion price of approximately $254.34 per share), only in the following circumstances and to the following extent: (1) during the five business-day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price per 2019 and 2021 Note for each day of such measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such day; (2) during any calendar quarter (and only during that quarter) after the calendar quarter ending September 30, 2014, if the last reported sale price of the Company’s common stock for 20 or more trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter exceeds 130% of the applicable conversion price in effect on the last trading day of the immediately preceding calendar quarter; (3) upon the occurrence of specified events described in the indenture for the 2019 and 2021 Notes; and (4) at any time on or after March 15, 2019 for the 2019 Notes, or March 15, 2021 for the 2021 Notes, through the second scheduled trading day immediately preceding the maturity date.
	As noted in the indentures for the 2019 and 2021 Notes, it is the Company's intent and policy to settle conversions through combination settlement, which essentially involves repayment of an amount of cash equal to the “principal portion” and delivery of the “share amount” in excess of the conversion value over the principal portion in shares of common stock. In general, for each $1,000 in principal the “principal portion” of cash upon settlement is defined as the lesser of $1,000 and the conversion value during the 20-day observation period. The conversion value is the sum of the daily conversion value which is the product of the effective conversion rate divided by 20 days and the daily volume weighted average price (VWAP) of the Company's common stock. The “share amount” is the cumulative “daily share amount” during the observation period, which is calculated by dividing the daily VWAP into the difference between the daily conversion value (i.e., conversion rate x daily VWAP) and $1,000.
	The 2019 Notes carry no coupon interest. The Company pays 0.5% interest per annum on the principal amount of the 2021 Notes, payable semiannually in arrears in cash on June 15 and December 15 of each year, beginning on December 15, 2014. The 2019 and 2021 Notes mature on June 15, 2019 and June 15, 2021, respectively. If a designated event, as defined in the indentures for the 2019 and 2021 Notes, such as acquisition, merger, or liquidation, occurs prior to the maturity date, subject to certain limitations, holders of the notes may require the Company to repurchase all or a portion of their notes for cash at a repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the repurchase date.
	The Company accounts separately for the liability and equity components of the 2019 and 2021 Notes in accordance with authoritative guidance for convertible debt instruments that may be settled in cash upon conversion. The guidance requires the carrying amount of the liability component to be estimated by measuring the fair value of a similar liability that does not have an associated conversion feature. Because the Company has no outstanding non-convertible public debt, the Company determined that market-traded senior, unsecured corporate bonds represent a similar liability to the convertible senior notes without the conversion option. Based on market data available for publicly traded, senior, unsecured corporate bonds issued by companies in the same industry as the Company, and with similar maturities to the 2019 and 2021 Notes, the Company estimated the implied interest rates of its 2019 and 2021 Notes to be 2.9% and 3.5%, respectively, assuming no conversion option. Assumptions used in the estimate represent what market participants would use in pricing the liability component, including market interest rates, credit standing, and yield curves, all of which are defined as Level 2 observable inputs. The estimated implied interest rates were applied to the 2019 and 2021 Notes, which resulted in a fair value of the liability component in aggregate of $971.5 million upon issuance, calculated as the present value of implied future payments based on the $1,150.0 million aggregate principal amount. The $161.2 million difference between the cash proceeds of $1,132.7 million and the estimated fair value of the liability component was recorded in additional paid-in capital as the 2019 and 2021 Notes are not considered redeemable.
	As a policy election under applicable guidance related to the calculation of diluted net income per share, the Company elected the combination settlement method as its stated settlement policy and applied the treasury stock method in the calculation of the potential dilutive impact of the 2019 and 2021 Notes. Neither the 2019 nor the 2021 Notes were convertible as of December 28, 2014 and had no dilutive impact during the year ended December 28, 2014. If the 2019 and 2021 Notes were converted as of December 28, 2014, the if-converted value would not exceed the principal amount.
	0.25% Convertible Senior Notes due 2016
	In 2011, the Company issued $920.0 million aggregate principal amount of 0.25% convertible senior notes due 2016 (2016 Notes) in an offering conducted in accordance with Rule 144A under the Securities Act of 1933, as amended. The 2016 Notes were issued at 98.25% of par value. Debt issuance costs of approximately $0.4 million were primarily comprised of legal, accounting, and other professional fees, the majority of which were recorded in other noncurrent assets and are being amortized to interest expense over the five-year term of the 2016 Notes.
	The 2016 Notes are convertible into cash, shares of common stock, or a combination of cash and shares of common stock, at the Company’s election, based on an initial conversion rate, subject to adjustment, of 11.9687 shares per $1,000 principal amount of the 2016 Notes (which represents an initial conversion price of approximately $83.55 per share), only in the following circumstances and to the following extent: (1) during the five business-day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price per 2016 Note for each day of such measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such day; (2) during any calendar quarter (and only during that quarter) after the calendar quarter ending March 31, 2011, if the last reported sale price of the Company’s common stock for 20 or more trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter exceeds 130% of the applicable conversion price in effect on the last trading day of the immediately preceding calendar quarter; (3) upon the occurrence of specified events described in the indenture for the 2016 Notes; and (4) at any time on or after December 15, 2015 through the second scheduled trading day immediately preceding the maturity date. Based upon meeting the stock trading price conversion requirement during the three months ended March 30, 2014, the 2016 Notes became convertible on April 1, 2014 and continue to be convertible through March 31, 2015. As such, the remaining 2016 Notes outstanding were classified as current liabilities as of December 28, 2014.
	As noted in the indenture for the 2016 Notes, it is the Company’s intent and policy to settle conversions through combination settlement, which essentially involves repayment of an amount of cash equal to the “principal portion” and delivery of the “share amount” in excess of the conversion value over the principal portion in shares of common stock. In general, for each $1,000 in principal, the “principal portion” of cash upon settlement is defined as the lesser of $1,000, and the conversion value during the 20-day observation period as described in the indenture for the 2016 Notes. The conversion value is the sum of the daily conversion value which is the product of the effective conversion rate divided by 20 days and the daily volume weighted average price (“VWAP”) of the Company’s common stock. The “share amount” is the cumulative “daily share amount” during the observation period, which is calculated by dividing the daily VWAP into the difference between the daily conversion value (i.e., conversion rate x daily VWAP) and $1,000. The Company pays 0.25% interest per annum on the principal amount of the 2016 Notes semiannually in arrears in cash on March 15 and September 15 of each year. The 2016 Notes mature on March 15, 2016. If a designated event, as defined in the indenture for the 2016 Notes, such as an acquisition, merger, or liquidation, occurs prior to the maturity date, subject to certain limitations, holders of the 2016 Notes may require the Company to repurchase all or a portion of their 2016 Notes for cash at a repurchase price equal to 100% of the principal amount of the 2016 Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the repurchase date.
	The Company accounts separately for the liability and equity components of the 2016 Notes in accordance with authoritative guidance for convertible debt instruments that may be settled in cash upon conversion. The guidance requires the carrying amount of the liability component to be estimated by measuring the fair value of a similar liability that does not have an associated conversion feature. Because the Company has no outstanding non-convertible public debt, the Company determined that senior, unsecured corporate bonds traded on the market represent a similar liability to the convertible senior notes without the conversion option. Based on market data available for publicly traded, senior, unsecured corporate bonds issued by companies in the same industry and with similar maturity, the Company estimated the implied interest rate of its 2016 Notes to be 4.5%, assuming no conversion option. Assumptions used in the estimate represent what market participants would use in pricing the liability component, including market interest rates, credit standing, and yield curves, all of which are defined as Level 2 observable inputs. The estimated implied interest rate was applied to the 2016 Notes, which resulted in a fair value of the liability component of $748.5 million upon issuance, calculated as the present value of implied future payments based on the $920.0 million aggregate principal amount. The $155.4 million difference between the cash proceeds of $903.9 million and the estimated fair value of the liability component was recorded in additional paid-in capital as the 2016 Notes were not considered redeemable.
	In conjunction with the issuance of the 2019 and 2021 Notes, the Company used the net proceeds from the issuance plus cash on hand to repurchase $600.0 million in principal amount of the outstanding 2016 Notes in privately negotiated transactions. The aggregate cash used for the repurchase was $1,244.7 million. The repurchase is accounted for as an extinguishment of debt. Extinguishment accounting requires the purchase price to be allocated to the liability and equity components of the repurchased notes based on the fair value of the liability component, and the difference between the fair value and the carrying value of the liability component to be recognized as loss on extinguishment of debt. An interest rate of 1.2% upon settlement, which was estimated using Level 2 inputs, was applied to measure the fair value of the liability component of the extinguished debt. This calculation resulted in $588.8 million allocated to the debt component and $655.9 million allocated to the equity component. The $31.4 million difference between the $588.8 million fair value of debt component and the carrying value of the repurchased 2016 Notes was recorded as a loss on extinguishment of debt within other expense, net, during the three and six months ended June 29, 2014. The $655.9 million of the repurchase price allocated to the equity component was recorded as a reduction of additional paid-in capital.
	As a policy election under applicable guidance related to the calculation of diluted net income per share, the Company elected the combination settlement method as its stated settlement policy and applied the treasury stock method in the calculation of dilutive impact of the 2016 Notes. During the years ended December 29, 2013 and December 30, 2012, the 2016 Notes were not convertible. However, as the market price of the Company’s common stock exceeded the conversion price during the last months of 2013, the calculation of dilutive potential common shares outstanding for the year ended December 29, 2013 reflects the dilutive impact from the 2016 Notes. The 2016 Notes had no dilutive impact for the year ended December 30, 2012. If the 2016 Notes were converted as of December 28, 2014, the if-converted value would exceed the principal amount by $393.3 million.
	0.625% Convertible Senior Notes due 2014
	In 2007, the Company issued $400.0 million principal amount of 0.625% convertible senior notes due 2014 (2014 Notes). The Company pays 0.625% interest per annum on the principal amount of the 2014 Notes semi-annually in arrears in cash on February 15 and August 15 of each year. The 2014 Notes matured on February 15, 2014. The effective interest rate of the liability component was estimated to be 8.3%.
	The Company entered into hedge transactions concurrently with the issuance of the 2014 Notes under which the Company was entitled to purchase up to approximately 18.3 million shares of the Company’s common stock at a strike price of approximately $21.83 per share, subject to adjustment. The convertible note hedge transactions had the effect of reducing dilution to the Company’s stockholders upon conversion of the 2014 Notes. Also concurrently with the issuance of the 2014 Notes, the Company sold to the hedge counterparties warrants exercisable, on a cashless basis, for up to approximately 18.3 million shares of the Company’s common stock at a strike price of $31.435 per share, subject to adjustment. The proceeds from these warrants partially offset the cost to the Company of the convertible note hedge transactions.
	The 2014 Notes were convertible into cash and shares of the Company’s common stock in various prior periods and became convertible again from April 1, 2012 through, and including, February 12, 2014, by which date all notes were converted. In all cases of conversions of the 2014 Notes, the principal amount converted was repaid with cash and the excess of the conversion value over the principal amount was paid in shares of common stock. The equity dilution resulting from the issuance of common stock related to the conversion of the 2014 Notes was offset by repurchase of the same amount of shares under the convertible note hedge transactions, which were automatically exercised in accordance with their terms at the time of each conversion. Accordingly, the hedge transactions terminated concomitant with the conversions of the 2014 Notes.
	As a result of the conversions during the year ended December 28, 2014, the Company recorded losses on extinguishment of debt calculated as the difference between the estimated fair value of the debt and the carrying value of the notes as of the settlement dates. To measure the fair value of the converted notes as of the settlement dates, the applicable interest rates were estimated using Level 2 observable inputs and applied to the converted notes using the same methodology as in the issuance date valuation.
	The following table summarizes information about the conversion of the 2014 Notes during the year ended December 28, 2014 (in thousands):
		2014 Notes
	Cash paid for principal of notes converted	$	29,570
	Conversion value over principal amount paid in shares of common stock	$	196,095
	Number of shares of common stock issued upon conversion	1,151
	The following table summarizes information about the equity and liability components of all convertible senior notes outstanding as of the period reported (dollars in thousands). The fair values of the respective notes outstanding were measured based on quoted market prices.
		December 28,			December 29, 2013
		2014
	Principal amount of convertible notes outstanding	$	1,470,027		$	949,570
	Unamortized discount of liability component	(178,991		)	(80,977		)
	Net carrying amount of liability component	1,291,036			868,593
	Less: current portion	(304,256		)	(29,288		)
	Long-term debt	$	986,780		$	839,305
	Conversion option subject to cash settlement	—			$	282
	Carrying value of equity component, net of issuance costs	$	215,283		$	274,304
	Fair value of outstanding notes	$	2,021,750		$	1,428,743
	Weighted average remaining amortization period of discount on the liability component	5.2 years			2.2 years

Commitments

Commitments	12 Months Ended
	Dec. 28, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments	Commitments
	Leases
	The Company leases office and manufacturing facilities under various noncancellable lease agreements. Facility leases generally provide for periodic rent increases, and many contain escalation clauses and renewal options. Certain leases require the Company to pay property taxes and routine maintenance. The Company is headquartered in San Diego, California and leases facilities in San Diego and the San Francisco Bay Area in California; Madison, Wisconsin; Morrisville, North Carolina; Australia; Brazil; China; France; Japan; Singapore; the Netherlands; and the United Kingdom.
	On December 30, 2014, the Company entered into a lease agreement, under the terms of which the Company will lease certain office buildings to be constructed at 200-800 Lincoln Centre Drive, Foster City, California, consisting of approximately 360,000 rentable square feet. In addition, the Company has the right to further expand the premises and lease an additional office building that may be built at this facility (the "Expansion Building"). The lease is for a period of 16 years (the "Initial Term") with a target commencement date of July 1, 2017. The Company has three five-year options to extend the lease. The aggregate rent during the Initial Term of the lease is expected to be approximately $204.0 million, but not including the Expansion Building.  The future minimum payments under this lease is not included in the table below. In addition to rent, the lease requires the Company to pay certain taxes, insurance, and operating costs relating to the leased buildings.
	During 2013, the Company entered into an agreement to sublease sections of its former headquarters. The sublease has an initial term of approximately ten years. In conjunction with the sublease, the Company issued a letter of credit in the amount of $8.0 million, which will decrease ratably to zero over the term of the sublease. As of December 28, 2014, the letter of credit carried a balance of $7.2 million.
	Annual future minimum payments under operating leases as of December 28, 2014 were as follows (in thousands):
		Operating			Sublease			Net Operating
		Leases			Income			Leases
	2015	$	35,210		$	(2,900	)	$	32,310
	2016	38,892			(2,924		)	35,968
	2017	37,064			(2,708		)	34,356
	2018	37,747			(2,789		)	34,958
	2019	39,656			(2,873		)	36,783
	Thereafter	415,052			(11,837		)	403,215
	Total minimum lease payments	$	603,621		$	(26,031	)	$	577,590
	Rent expense was $33.2 million, $28.1 million, and $21.4 million for the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively.
	The Company recorded facility exit obligations upon vacating its former headquarters in 2011. Changes in the facility exit obligation from January 1, 2012 through December 28, 2014 are as follows (in thousands):
		Facility Exit Obligation
	Balance as of January 1, 2012:	$	25,049
	Adjustment to facility exit obligation	24,878
	Accretion of interest expense	2,129
	Cash payments	(6,704		)
	Balance as of December 30, 2012	45,352
	Adjustment to facility exit obligation	(114		)
	Accretion of interest expense	2,738
	Cash payments	(9,758		)
	Balance as of December 29, 2013	38,218
	Adjustment to facility exit obligation	2,555
	Accretion of interest expense	2,638
	Cash payments	(5,711		)
	Balance as of December 28, 2014	$	37,700
	Licensing Agreements
	In the normal course of its business, the Company enters, from time to time, into licensing agreements under which the Company commits to certain minimum royalty payments, some of which are subject to adjustment. Such licensing agreements may be terminated prior to the expiration of underlying intellectual property under certain circumstances. Annual future minimum royalty payments under the Company’s licensing agreements as of December 28, 2014 are as follows (in thousands):
		Minimum Payments
	2015	$	8,650
	2016	12,470
	2017	13,500
	2018	18,475
	2019	23,480
	Thereafter	23,550
	Total minimum royalty payments	$	100,125
	Warranties
	Changes in the Company’s reserve for product warranties from January 1, 2012 through December 28, 2014 are as follows (in thousands):
		Warranty Reserve
	Balance as of January 1, 2012	$	11,966
	Additions charged to cost of revenue	17,279
	Repairs and replacements	(19,109		)
	Balance as of December 30, 2012	10,136
	Additions charged to cost of revenue	15,674
	Repairs and replacements	(15,403		)
	Balance as of December 29, 2013	10,407
	Additions charged to cost of revenue	24,150
	Repairs and replacements	(18,941		)
	Balance as of December 28, 2014	$	15,616

Sharebased_Compensation_Expens

Share-based Compensation Expense	12 Months Ended
	Dec. 28, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Expense	Share-based Compensation Expense
	Share-based compensation expense for all stock awards consists of the following (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Cost of product revenue	$	9,451		$	6,223		$	7,575
	Cost of service and other revenue	1,204			777			461
	Research and development	50,880			37,439			30,879
	Selling, general and administrative	91,016			61,387			55,409
	Share-based compensation expense before taxes	152,551			105,826			94,324
	Related income tax benefits	(44,194		)	(32,819		)	(30,759		)
	Share-based compensation expense, net of taxes	$	108,357		$	73,007		$	63,565
	The assumptions used for the specified reporting periods and the resulting estimates of weighted-average grant date fair value per share of options granted and for stock purchased under the ESPP are as follows:
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Stock options granted:
	Risk-free interest rate	—			0.14 - 1.86%			0.56 - 0.93%
	Expected volatility	—			30 - 44%			41 - 48%
	Expected term	—			0.8 - 9.4 years			4.0 - 6.6 years
	Expected dividends	—			—			—
	Weighted-average grant-date fair value per share	—			$	40.66		$	15.47
	Stock purchased under the ESPP:
	Risk-free interest rate	0.05 - 0.13%			0.08 - 0.15%			0.09 - 0.17%
	Expected volatility	38% - 41%			31 - 32%			33 - 64%
	Expected term	0.5 - 1.0 year			0.5 - 1.0 year			0.5 - 1.0 year
	Expected dividends	—			—			—
	Weighted-average grant-date fair value per share	$	44.64		$	19.3		$	16.45
	As of December 28, 2014, approximately $280.6 million of total unrecognized compensation cost related to stock options, restricted stock, and ESPP shares issued to date is expected to be recognized over a weighted-average period of approximately 2.1 years.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 28, 2014
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity
	The Company’s 2005 Stock and Incentive Plan (the 2005 Stock Plan), 2005 Solexa Equity Incentive Plan (the 2005 Solexa Equity Plan), the Verinata Health, Inc. 2008 Stock Plan (the 2008 Stock Plan), and the New Hire Stock and Incentive Plan allow for the issuance of stock options, restricted stock units and awards, and performance stock units. During the year ended December 29, 2013, the stockholders ratified an amendment to increase the maximum number of shares of common stock authorized for issuance under the 2005 Stock Plan by 5.0 million shares. As of December 28, 2014, approximately 5.3 million shares remained available for future grants under the 2005 Stock Plan, the 2005 Solexa Equity Plan, and the 2008 Verinata Health Stock Plan. There is no set number of shares reserved for issuance under the New Hire Stock and Incentive Plan.
	Stock Options
	Stock options granted at the time of hire primarily vest over a four or five-year period, with 25% or 20% of options vesting on the first anniversary of the grant date and the remaining options vesting monthly over the remaining vesting period. Stock options granted subsequent to hiring primarily vest monthly over a four or five-year period. Each grant of options has a maximum term of ten years, measured from the applicable grant date, subject to earlier termination if the optionee’s service ceases. Vesting in all cases is subject to the individual’s continued service through the vesting date. The Company satisfies option exercises through the issuance of new shares.
	The Company’s stock option activity under all stock option plans from January 1, 2012 through December 28, 2014 is as follows:
		Options		Weighted-
		(in thousands)		Average
				Exercise Price
	Outstanding at January 1, 2012	10,378		$	29.69
	Granted	251		$	40.79
	Exercised	(2,071	)	$	20.34
	Cancelled	(207	)	$	39.18
	Outstanding at December 30, 2012	8,351		$	32.1
	Granted	512		$	14.74
	Exercised	(3,006	)	$	27.7
	Cancelled	(133	)	$	41.8
	Outstanding at December 29, 2013	5,724		$	32.64
	Exercised	(2,478	)	$	29.93
	Cancelled	(35	)	$	31.73
	Outstanding at December 28, 2014	3,211		$	34.74
	At December 28, 2014, outstanding options to purchase 2.9 million shares were exercisable with a weighted-average per share exercise price of $35.94. The weighted-average remaining life of options outstanding and exercisable is 4.3 years and 4.1 years, respectively, as of December 28, 2014.
	The aggregate intrinsic value of options outstanding and options exercisable as of December 28, 2014 was $492.8 million and $444.2 million, respectively. Aggregate intrinsic value represents the product of the number of options outstanding multiplied by the difference between the Company’s closing stock price per share on the last trading day of the fiscal period, which was $188.20 as of December 26, 2014, and the exercise price. Total intrinsic value of options exercised was $330.5 million, $141.7 million, and $60.6 million for the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively. Total fair value of options vested was $17.2 million, $24.0 million, and $31.9 million for the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively.
	Restricted Stock
	The Company issues restricted stock units (RSU), restricted stock awards (RSA), and performance stock units (PSU). The Company grants RSU and PSU pursuant to its 2005 Stock and Incentive Plan and 2008 Stock Plan. RSU are share awards that, upon vesting, will deliver to the holder shares of the Company’s common stock. For grants to new hires prior to July 2011 and for grants to existing employees, RSU generally vest 15% on the first anniversary of the grant date, 20% on the second anniversary of the grant date, 30% on the third anniversary of the grant date, and 35% on the fourth anniversary of the grant date. For grants to new hires subsequent to July 2011, RSU generally vest over a four-year period with equal vesting on anniversaries of the grant date. The Company satisfies RSU vesting through the issuance of new shares. The Company issues PSU for which the number of shares issuable at the end of a three-year performance period can reach up to 150% of the shares approved in the award based on the Company’s performance relative to specified earnings per share targets.
	The Company also issues RSA that are released based on service related vesting conditions. RSA may be issued from the Company’s treasury stock or granted pursuant to the Company’s 2005 Stock and Incentive Plan.
	A summary of the Company’s restricted stock activity and related information from January 1, 2012 through December 28, 2014 is as follows (in thousands, except per share amounts):
		Restricted		Restricted			Performance			Weighted-Average
		Stock Awards		Stock Units			Stock Units			Grant-Date Fair Value per Share
		(RSA)		(RSU)			(PSU)			RSA		RSU		PSU
	Outstanding at January 1, 2012	230		3,476			—			$	65.95	$	41.87	—
	Awarded	312		1,640			599			$	47.91	$	48.52	$	49.66
	Vested	(77	)	(1,062	)		—			$	65.95	$	38.48	—
	Cancelled	—		(394	)		(12	)		—		$	45.05	$	50.54
	Outstanding at December 30, 2012	465		3,660			587			$	53.84	$	45.49	$	49.64
	Awarded	—		1,532			584			—		$	77.53	$	59.16
	Vested	(217	)	(1,308	)		—			$	54.27	$	42.97	—
	Cancelled	—		(256	)		(70	)		—		$	49.24	$	50.42
	Outstanding at December 29, 2013	248		3,628			1,101			$	53.46	$	59.66	$	54.64
	Awarded	—		780			968			—		$	172.53	$	104.52
	Vested	(140	)	(1,383	)		(753	)		$	47.9	$	55.44	$	49.52
	Cancelled	—		(184	)		(59	)		—		$	65.09	$	52.87
	Outstanding at December 28, 2014	108		2,841			1,257			$	56.62	$	92.35	$	96.21
	Pre-tax intrinsic values and total fair value of vested restricted stock are as follows (in thousands):
		Years Ended
		December 28,			December 29,				December 30,
		2014			2013				2012
	Pre-tax intrinsic value of outstanding restricted stock:
	RSA	$	20,321		$	27,384			$	25,437
	RSU	$	534,708		$	400,421			$	200,383
	PSU	$	236,606		$	121,555			$	32,149
	Fair value of restricted stock vested:
	RSA	$	6,712		$	11,750			$	5,039
	RSU	$	76,646		$	56,212			$	40,870
	PSU	$	37,313		—				—
	Employee Stock Purchase Plan
	A total of 15.5 million shares of the Company’s common stock have been reserved for issuance under its 2000 Employee Stock Purchase Plan, or ESPP. The ESPP permits eligible employees to purchase common stock at a discount, but only through payroll deductions, during defined offering periods. The price at which stock is purchased under the ESPP is equal to 85% of the fair market value of the common stock on the first or last day of the offering period, whichever is lower. The initial offering period commenced in July 2000.
	The ESPP provides for annual increases of shares available for issuance by the lesser of 3% of the number of outstanding shares of the Company’s common stock on the last day of the immediately preceding fiscal year, 3.0 million shares, or such lesser amount as determined by the Company’s board of directors. Approximately 0.3 million, 0.4 million, and 0.3 million shares were issued under the ESPP during the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively. As of December 28, 2014 and December 29, 2013, there were approximately 14.7 million and 15.0 million shares available for issuance under the ESPP, respectively.
	Warrants
	In connection with the offering of the Company’s 2014 Notes, the Company sold warrants to purchase 18.3 million shares of common stock to counterparties to the convertible note hedge transactions. The warrants have an exercise price of $31.435 per share, and the proceeds from the sale of such warrants were used by the Company to partially offset the cost of the transactions. In July 2013, the Company settled with a hedging counterparty outstanding warrants to purchase approximately 3.0 million shares of the Company’s common stock for $125.0 million in cash. The remaining warrants were exercised in full during the year ended December 28, 2014.
	Share Repurchases
	During the years ended December 28, 2014, December 29, 2013, and December 30, 2012, the Company repurchased approximately 1.5 million shares for $237.2 million, 0.9 million shares for $50.0 million, and 1.9 million shares for $82.5 million, respectively.
	In April 2012, the Company’s Board of Directors authorized share repurchases for up to $250.0 million via a combination of Rule 10b5-1 and discretionary share repurchase programs. In addition, on January 30, 2014, the Company’s Board of Directors authorized up to $250.0 million to repurchase shares of the Company’s common stock on a discretionary basis. Authorizations to repurchase up to an additional $130.4 million of its common stock remained as of December 28, 2014.
	Stockholder Rights Plan
	In connection with the unsolicited tender offer by Roche (refer to note “15. Unsolicited Tender Offer”), on January 25, 2012, the Company’s Board of Directors declared a dividend of one preferred share purchase right (Right) for each outstanding share of the Company’s common stock. Each Right entitled the registered holder to purchase from the Company one one-thousandth of a share of the Company’s Series A Junior Participating Preferred Stock, par value $0.01 per share (Preferred Shares), at a price of $275.00 per one thousandth of a Preferred Share, subject to adjustment. The Rights were not exercisable until such time that the Board of Directors determined to eliminate its deferral of the date on which separate Rights certificates are issued and the Rights traded separately from the Company’s common stock (Distribution Date). If a person or group (triggering party) acquired 15% or more of the Company’s outstanding common stock, each Right would have entitled holders other than the triggering party to purchase, at the exercise price of the Right, a number of shares of common stock having a market value of two times the exercise price of the Right. If the Company was acquired in a merger or other business combination transaction after a person acquires 15% or more of the Company’s common stock, each Right would have entitled holders other than the triggering party to purchase, at the Right’s then-current exercise price, a number of common shares of the acquiring company that at the time of such transaction have a market value of two times the exercise price of the Right. The Board of Directors would have been entitled to redeem the Rights at a price of $0.001 per Right at any time before the Distribution Date. The Board of Directors would have been entitled to exchange the Rights at an exchange ratio per Right of one share of common stock after any person acquires beneficial ownership of 15% or more of the Company’s outstanding common stock, and prior to the acquisition of 50% or more of the Company’s outstanding common stock. In 2013, the expiration date was amended to March 27, 2013, from January 26, 2017, and the Rights expired accordingly.

Legal_Proceedings

Legal Proceedings	12 Months Ended
	Dec. 28, 2014
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	Legal Proceedings
	The Company is involved in various lawsuits and claims arising in the ordinary course of business, including actions with respect to intellectual property, employment, and contractual matters. In connection with these matters, the Company assesses, on a regular basis, the probability and range of possible loss based on the developments in these matters. A liability is recorded in the financial statements if it is believed to be probable that a loss has been incurred and the amount of the loss can be reasonably estimated. Because litigation is inherently unpredictable and unfavorable results could occur, assessing contingencies is highly subjective and requires judgments about future events. The Company regularly reviews outstanding legal matters to determine the adequacy of the liabilities accrued and related disclosures. The amount of ultimate loss may differ from these estimates. Each matter presents its own unique circumstances, and prior litigation does not necessarily provide a reliable basis on which to predict the outcome, or range of outcomes, in any individual proceeding. Because of the uncertainties related to the occurrence, amount, and range of loss on any pending litigation or claim, the Company is currently unable to predict their ultimate outcome, and, with respect to any pending litigation or claim where no liability has been accrued, to make a meaningful estimate of the reasonably possible loss or range of loss that could result from an unfavorable outcome. In the event that opposing litigants in outstanding litigations or claims ultimately succeed at trial and any subsequent appeals on their claims, any potential loss or charges in excess of any established accruals, individually or in the aggregate, could have a material adverse effect on the Company’s business, financial condition, results of operations, and/or cash flows in the period in which the unfavorable outcome occurs or becomes probable, and potentially in future periods.
	Syntrix
	On November 24, 2010, Syntrix Biosystems, Inc. (“Syntrix”) filed suit against the Company in the United States District Court for the Western District of Washington at Tacoma (Case No. C10-5870-BHS) alleging that the Company willfully infringed U.S. Patent No. 6,951,682 by selling its BeadChip array products, and that the Company misappropriated Syntrix’s trade secrets. On January 30, 2013, the Court granted the Company’s motion for summary judgment on Syntrix’s trade secret claims, and dismissed those claims from the case. On March 14, 2013, a jury reached a verdict in favor of Syntrix, finding that Illumina’s BeadChip kits infringe the Syntrix patent. During trial, the Court dismissed Syntrix’s claim that the alleged infringement was willful. On July 1, 2013, the Court entered a Final Amended Judgment for $115.1 million, in accordance with the jury verdict, including supplemental damages and prejudgment interest. In addition, the Court awarded Syntrix an ongoing royalty of 8% for accused sales from March 15, 2013 until the patent expires on September 16, 2019. On December 3, 2013, the Company filed a Notice of Appeal to the Court of Appeals for the Federal Circuit challenging the Final Amended Judgment. On December 16, 2013, Syntrix cross appealed the Court’s dismissal of its trade secret claims and denial of its willfulness claim. For the year ended December 29, 2013, the Company recorded total charges of $132.9 million related to this matter, $114.6 million of which was recorded within operating expenses, with the remainder recorded to cost of sales.
	On November 14, 2014, the Company entered into a Settlement and License Agreement with Syntrix and its sole shareholders, John A. Zebala and Amy Zebala, that settled all claims in the litigation. Pursuant to the terms of the Settlement and License Agreement, the Company paid Syntrix a one-time payment of $70.0 million in exchange for a release of past damages claimed and a fully paid-up exclusive license to U.S. Patent No. 6,951,682.  None of the parties made any admission of liability in entering into the Settlement and License Agreement. On November 19, 2014, the Court dismissed the litigation with prejudice and vacated the judgment against the Company. The Company allocated the $70.0 million payment on relative fair value basis, resulting in $29.5 million capitalized as an intangible asset for the value of the exclusive license, which is amortized over a period of 4.8 years on a straight-line basis, and the remaining $40.5 million to the release of past damages claimed. The fair value of license and past damages was estimated using a discounted cash flow model, and is considered to be a Level 3 measurement.
	As of September 28, 2014, the Company had accrued $148.8 million for damages and interest awarded to Syntrix. The settlement of the litigation resulted in a gain of $109.4 million, calculated as the difference between the accrual released and the amount of payment allocated to the release of past damages claimed. $27.3 million of the total gain was recorded as reversal of cost of sales, reflecting a true-up of historical royalty expenses to the effective royalty rate. The remaining gain of $82.1 million was recorded as a legal contingency gain in operating expenses. In conjunction with the settlement, a $33.5 million deposit with the Court, which was reported in prepaid expenses, was released.
	Sequenom
	On December 2, 2014, the Company and its subsidiary Verinata Health, Inc. entered into a series of agreements with Sequenom, Inc. (“Sequenom”), its subsidiary Sequenom Center for Molecular Medicine LLC (“Sequenom LLC”), and Chinese University of Hong Kong (“CUHK”), and an agreement with the Trustees of Leland Stanford University (“Stanford”), that, together, (1) settled a patent litigation pending in the United States District Court for the Northern District of California (the “District Court”) between Verinata and Stanford, on the one hand, and Sequenom, Sequenom LLC, and Isis Innovation Limited (“Isis”), on the other hand, (2) requested remand of certain claims and counterclaims of Sequenom, Isis, Verinata, and Stanford from the appeal pending in the United States Court of Appeals for the Federal Circuit of a second patent litigation pending in District Court in order to seek to vacate an order related to those claims and dismiss them, and (3) settled an inter partes review related to a United States Patent No. 8,195,415, assigned to Stanford and licensed to Verinata.
	As part of the settlement, the Company and Sequenom have entered into a Pooled Patents Agreement and related sublicense agreements whereby (1) Sequenom granted Illumina a worldwide license to patents directed to Non-Invasive Prenatal Testing (“NIPT”) for Laboratory Developed Testing (“LDT”) and In-Vitro Diagnostic (“IVD”) products, which license is exclusive in the LDT field, except with respect to certain patents formerly owned by Isis, in which case it is non-exclusive, and (2) Illumina (and Verinata in some cases) granted a worldwide non-exclusive license to Sequenom under Illumina-owned and in-licensed NIPT-related patents for Sequenom to continue its business related to NIPT LDT (the patents owned or in-licensed by either the Company or Sequenom that fall under the Pooled Patents Agreement are the “Pooled Patents”). The Company also assumed, by novation, amended exclusive patent licenses from CUHK to Sequenom and entered into several new exclusive in-license agreements with CUHK related to CUHK patents directed to NIPT, and granted to Sequenom non-exclusive sublicenses under the Company’s license agreements with CUHK, Stanford, and General Hospital Corporation for Sequenom to practice NIPT LDT. The Company and Sequenom also extended, amended, and restated their current supply agreement under which Sequenom purchases from the Company equipment and supplies for NIPT LDT and other clinical fields, and entered into a separate agreement whereby Sequenom transferred to the Company certain clinical samples and data useful in the development of NIPT IVD.
	As consideration for the foregoing settlement arrangements, the Company agreed to pay Sequenom an aggregate of $50.0 million, as well as to pay royalties to Sequenom for sales of NIPT IVD products. The Company and Sequenom also agreed to share revenues received for exploitation of the Pooled Patents in NIPT LDT. None of the parties made any admission of liability in entering into these arrangements. The parties filed certain stipulated motions with the Federal Circuit and District Court to vacate and dismiss the associated claims and counterclaims with prejudice, which motions have been granted by the respective courts.
	The Company considered whether the elements received represented identifiable benefits that were sufficiently separable from the products it sells to Sequenom, and considered whether the value of these benefits could be reasonably estimated. The Company identified the legal settlement, clinical samples, the IVD and LDT patent rights as elements. The Company used a discounted cash flow analysis to estimate the value of the patent rights, replacement cost to value the samples, and an assumed royalty rate on historical sales for the legal settlement. These fair value estimates are considered Level 3 measurements. The Company determined that the aggregate fair value of the benefits received exceeded the consideration paid and allocated the $50.0 million payment to the various elements on a relative fair value basis. This resulted in $48.8 million allocated to the samples and patent rights transferred to Illumina, which were expensed in research and development expenses due to lack of alternative future use.  The remaining $1.2 million was recorded as a legal contingency charge in operating expenses.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 28, 2014
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes
	The income before income taxes summarized by region is as follows (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	United States	$	176,974		$	(53,703	)	$	102,296
	Foreign	271,784			213,017			120,312
	Total income before income taxes	$	448,758		$	159,314		$	222,608
	The provision for income taxes consists of the following (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Current:
	Federal	$	60,984		$	78,419		$	57,285
	State	12,381			8,854			10,121
	Foreign	41,815			39,416			31,504
	Total current provision	115,180			126,689			98,910
	Deferred:
	Federal	(3,191		)	(69,102		)	(7,724		)
	State	(4,974		)	(15,222		)	(7,708		)
	Foreign	(11,608		)	(8,359		)	(12,124		)
	Total deferred benefit	(19,773		)	(92,683		)	(27,556		)
	Total tax provision	$	95,407		$	34,006		$	71,354
	The provision for income taxes reconciles to the amount computed by applying the federal statutory rate to income before taxes as follows (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Tax at federal statutory rate	$	157,065		$	55,760		$	77,913
	State, net of federal benefit	5,023			647			4,056
	Research and other credits	(16,144		)	(10,977		)	(2,613		)
	Change in valuation allowance	(4,212		)	10,544			(37		)
	Change in fair value of contingent consideration	(1,321		)	(3,859		)	—
	Impact of foreign operations	(42,215		)	(18,006		)	(11,470		)
	Other	(2,789		)	(103		)	3,505
	Total tax provision	$	95,407		$	34,006		$	71,354
	The impact of foreign operations primarily represents the difference between the actual provision for income taxes for our legal entities that operate primarily in jurisdictions that have statutory tax rates lower than the U.S. federal statutory tax rate of 35%. The most significant tax benefits from foreign operations were from the Company’s earnings in Singapore and the United Kingdom, which had statutory tax rates of 17% and 21.5%, respectively, in the year ended December 28, 2014. The impact of foreign operations also includes the U.S. foreign tax credit impact of non-U.S. earnings and uncertain tax positions related to foreign items.
	Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):
		December 28,			December 29,
		2014			2013
	Deferred tax assets:
	Net operating losses	$	47,738		$	66,969
	Tax credits	32,192			36,277
	Other accruals and reserves	41,676			86,716
	Stock compensation	54,570			36,728
	Deferred rent	25,975			16,823
	Inventory adjustments	12,003			9,034
	Other amortization	28,203			9,571
	Other	24,045			18,244
	Total gross deferred tax assets	266,402			280,362
	Valuation allowance on deferred tax assets	(15,191		)	(19,132		)
	Total deferred tax assets	251,211			261,230
	Deferred tax liabilities:
	Purchased intangible amortization	(85,612		)	(98,671		)
	Convertible debt	(61,383		)	(27,821		)
	Property and equipment	(16,521		)	(13,311		)
	Other	(1,670		)	(6,349		)
	Total deferred tax liabilities	(165,186		)	(146,152		)
	Net deferred tax assets	$	86,025		$	115,078
	A valuation allowance is established when it is more likely than not the future realization of all or some of the deferred tax assets will not be achieved. The evaluation of the need for a valuation allowance is performed on a jurisdiction-by-jurisdiction basis, and includes a review of all available positive and negative evidence. Based on the available evidence as of December 28, 2014, the Company was not able to conclude it is more likely than not certain U.S. deferred tax assets will be realized. Therefore, the Company recorded a valuation allowance of $15.2 million against certain U.S. deferred tax assets. During the year ended December 28, 2014, the valuation allowance decreased by $3.9 million, primarily due to a $10.4 million decrease in the provision for income taxes related to foreign tax credits utilized in the U.S., offset by a $6.0 million increase in the provision for income taxes related to state research and development credits generated in the current year.
	As of December 28, 2014, the Company had net operating loss carryforwards for federal and state tax purposes of $163.6 million and $295.0 million, respectively, which will begin to expire in 2020 and 2015, respectively, unless utilized prior. The Company also had federal and state tax credit carryforwards of $15.3 million and $63.7 million, respectively, which will begin to expire in 2024 and 2019, respectively, unless utilized prior.
	Pursuant to Section 382 and 383 of the Internal Revenue Code, utilization of the Company’s net operating losses and credits may be subject to annual limitations in the event of any significant future changes in its ownership structure. These annual limitations may result in the expiration of net operating losses and credits prior to utilization. The deferred tax assets as of December 28, 2014 are net of any previous limitations due to Section 382 and 383.
	The Company recognizes excess tax benefits associated with share-based compensation to stockholders’ equity only when realized. When assessing whether excess tax benefits relating to share-based compensation have been realized, the Company follows the with-and-without approach excluding any indirect effects of the excess tax deductions. Under this approach, excess tax benefits related to share-based compensation are not deemed to be realized until after the utilization of all other tax benefits available to the Company. During the year ended December 28, 2014, the Company realized $126.5 million of such excess tax benefits, and accordingly recorded a corresponding credit to additional paid-in capital. As of December 28, 2014, the Company had $36.8 million of unrealized excess tax benefits associated with share-based compensation. These tax benefits will be accounted for as a credit to additional paid-in capital, if and when realized, rather than a reduction of the provision for income taxes.
	The Company’s manufacturing operations in Singapore operate under various tax holidays and incentives that begin to expire in 2018. For the year ended December 28, 2014, these tax holidays and incentives resulted in a $15.6 million decrease to the provision for income taxes and an increase in net income per diluted share of $0.10.
	It is the Company’s intention to indefinitely reinvest all current and future foreign earnings in order to ensure sufficient working capital to support and expand existing operations outside the United States. Accordingly, residual U.S. income taxes have not been provided on $395.6 million of undistributed earnings of foreign subsidiaries as of December 28, 2014. In the event the Company was required to repatriate funds from outside of the United States, such repatriation would be subject to local laws, customs, and tax consequences.
The following table summarizes the gross amount of the Company’s uncertain tax positions (in thousands):
	December 28,			December 29,			December 30,
	2014			2013			2012
Balance at beginning of year	$	49,046		$	37,585		$	28,396
Increases related to prior year tax positions	426			4,794			2,573
Decreases related to prior year tax positions	(804		)	(223		)	(69		)
Increases related to current year tax positions	8,756			7,503			6,685
Decreases related to lapse of statute of limitations	(5,336		)	(613		)	—
Balance at end of year	$	52,088		$	49,046		$	37,585
Included in the balance of uncertain tax positions as of December 28, 2014, and December 29, 2013, were $42.6 million and $40.1 million, respectively, of net unrecognized tax benefits that, if recognized, would reduce the Company’s effective income tax rate in future periods.
Any interest and penalties related to uncertain tax positions are reflected in the provision for income taxes. The Company recognized expense of $0.7 million, $1.0 million, and $0.8 million, related to potential interest and penalties on uncertain tax positions during the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively. The Company recorded a liability for potential interest and penalties of $4.4 million and $3.5 million as of December 28, 2014 and December 29, 2013, respectively.
The Company is currently under examination by the IRS for tax year 2011. The IRS has not yet proposed any adjustments to the filed return. Tax years 1997 to 2014 remain subject to future examination by the major tax jurisdictions in which the Company is subject to tax. Given the uncertainty of potential adjustments from the current examination as well as the impact of the current examination on the potential expiration of the statute of limitations, it is reasonably possible that the balance of unrecognized tax benefits could change significantly over the next 12 months. However, at this time, an estimate of the range of reasonably possible adjustments to the balance of unrecognized tax benefits cannot be determined given the number of matters being examined and the number of years that are potentially subject to examination.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 28, 2014
Postemployment Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans
	Retirement Plan
	The Company has a 401(k) savings plan covering substantially all of its employees in the United States. Company contributions to the plan are discretionary. During the years ended December 28, 2014, December 29, 2013, and December 30, 2012, the Company made matching contributions of $9.5 million, $7.0 million, and $5.5 million, respectively.
	Deferred Compensation Plan
	The Company adopted the Illumina, Inc. Deferred Compensation Plan (the Plan) that became effective January 1, 2008. The Company’s senior level employees can contribute up to 80% of their base salary and 100% of their variable cash compensation. Members of the board of directors can contribute up to 100% of their director fees and equity awards. The Company has agreed to credit the participants’ contributions with earnings that reflect the performance of certain independent investment funds. On a discretionary basis, the Company may also make employer contributions to participant accounts in any amount determined by the Company. The vesting schedules of employer contributions are at the sole discretion of the Compensation Committee. However, all employer contributions shall become 100% vested upon the occurrence of the participant’s disability, death or retirement or a change in control of the Company. The benefits under this plan are unsecured. Participants are generally eligible to receive payment of their vested benefit at the end of their elected deferral period or after termination of their employment with the Company for any reason or at a later date to comply with the restrictions of Section 409A. As of December 28, 2014, no employer contributions were made to the Plan.
	In January 2008, the Company also established a rabbi trust for the benefit of the participants under the Plan. In accordance with authoritative guidance related to consolidation of variable interest entities and accounting for deferred compensation arrangements where amounts earned are held in a rabbi trust and invested, the Company has included the assets of the rabbi trust in its consolidated balance sheet since the trust’s inception. As of December 28, 2014 and December 29, 2013, the assets of the trust were $23.5 million and $17.8 million, respectively, and liabilities of the Company were $20.3 million and $15.0 million, respectively. The assets and liabilities are classified as other assets and accrued liabilities, respectively, on the Company’s consolidated balance sheets. Changes in the values of the assets held by the rabbi trust are recorded in other (expense) income, net in the consolidated statements of income, and changes in the values of the deferred compensation liabilities are recorded in cost of sales or operating expenses.

Segment_Information_Geographic

Segment Information, Geographic Data, and Significant Customers	12 Months Ended
	Dec. 28, 2014
Segment Reporting [Abstract]
Segment Information, Geographic Data, and Significant Customers	Segment Information, Geographic Data, and Significant Customers
	The Company had revenue in the following regions for the years ended December 28, 2014, December 29, 2013, and December 30, 2012 (in thousands):
		Years Ended
		December 28,		December 29,		December 30,
		2014		2013		2012
	United States	$	950,703	$	714,662	$	568,443
	Europe	466,536		354,682		291,404
	Asia-Pacific	342,702		276,442		232,498
	Other markets	101,417		75,392		56,171
	Total	$	1,861,358	$	1,421,178	$	1,148,516
	Revenues are attributable to geographic areas based on the region of destination.
	The majority of our product sales consist of consumables and instruments. For the years ended December 28, 2014, December 29, 2013, and December 30, 2012, consumable sales represented 56%, 62%, and 64%, respectively, of total revenues and instrument sales comprised 30%, 26%, and 27%, respectively, of total revenues. The Company’s customers include leading genomic research centers, academic institutions, government laboratories, hospitals, and reference laboratories, as well as pharmaceutical, biotechnology, agrigenomics, commercial molecular diagnostic, and consumer genomics companies. The Company had no customers that provided more than 10% of total revenue in the years ended December 28, 2014, December 29, 2013, and December 30, 2012.
	Net long-lived assets exclude goodwill and other intangible assets since they are not allocated on a geographic basis. The Company had net long-lived assets consisting of property and equipment in the following regions as of December 28, 2014 and December 29, 2013 (in thousands):
		December 28,		December 29,
		2014		2013
	United States	$	204,717	$	150,470
	United Kingdom	31,965		24,122
	Singapore	22,326		21,311
	Other countries	6,256		6,763
	Total	$	265,264	$	202,666

Quarterly_Financial_Informatio

Quarterly Financial Information (unaudited)	12 Months Ended
	Dec. 28, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (unaudited)	Quarterly Financial Information (unaudited)
	The following financial information reflects all normal recurring adjustments, which are, in the opinion of management, necessary for a fair statement of the results and cash flows of interim periods. All quarters for fiscal years 2014 and 2013 ended December 28, 2014 and December 29, 2013 were 13 weeks. Summarized quarterly data for fiscal years 2014 and 2013 are as follows (in thousands, except per share amounts):
		First Quarter			Second Quarter		Third Quarter		Fourth Quarter
	2014
	Total revenue	$	420,781		$	447,568	$	480,630	$	512,379
	Gross profit	$	278,292		$	300,540	$	333,941	$	384,937
	Net income	$	59,977		$	46,605	$	93,489	$	153,280
	Net income per share, basic	$	0.47		$	0.36	$	0.66	$	1.08
	Net income per share, diluted	$	0.4		$	0.31	$	0.63	$	1.03
	2013
	Total revenue	$	330,958		$	346,094	$	356,800	$	387,326
	Gross profit	$	219,292		$	223,409	$	209,940	$	259,246
	Net (loss) income	$	(22,587	)	$	35,877	$	31,357	$	80,661
	Net (loss) income per share, basic	$	(0.18	)	$	0.29	$	0.25	$	0.64
	Net (loss) income per share, diluted	$	(0.18	)	$	0.26	$	0.22	$	0.56

SCHEDULE_II_VALUATION_AND_QUAL

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES	12 Months Ended
	Dec. 28, 2014
Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts and Reserves	VALUATION AND QUALIFYING ACCOUNTS AND RESERVES
		Balance at		Additions Charged		Deductions(2)		Balance at
		Beginning of		to Expenses/(Reductions from)				End of
		Period		Revenue(1)				Period
		(In thousands)
	Year ended December 28, 2014
	Allowance for doubtful accounts	$	3,680	1,870		(91	)	$	5,459
	Year ended December 29, 2013
	Allowance for doubtful accounts	$	4,280	(422	)	(178	)	$	3,680
	Year ended December 30, 2012
	Allowance for doubtful accounts	$	3,997	2,191		(1,908	)	$	4,280
	_______________________________________
	-1	Additions to and reductions from allowance for doubtful accounts are recorded to selling, general and administrative expense.
	-2	Deductions for allowance for doubtful accounts are for accounts receivable written off.

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 28, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The consolidated financial statements of the Company have been prepared in conformity with U.S. generally accepted accounting principles and include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
Fiscal Year	Fiscal Year
	The Company’s fiscal year is 52 or 53 weeks ending the Sunday closest to December 31, with quarters of 13 or 14 weeks ending the Sunday closest to March 31, June 30, September 30, and December 31. Each of the years ended December 28, 2014, December 29, 2013, and December 30, 2012 were 52 weeks.
Use of Estimates	Use of Estimates
	The preparation of financial statements requires that management make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses, and related disclosures of contingent assets and liabilities. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers. The new standard is based on the principle that revenue should be recognized 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. ASU 2014-09 will be effective for the Company beginning in the first quarter of 2017 and allows for a full retrospective or a modified retrospective adoption approach. The Company is currently evaluating the impact of ASU 2014-09 on its consolidated financial statements.
Segment Information	Segment Information
	Effective December 30, 2013, the Company reorganized and separated the roles of the Chief Executive Officer and the President, with core market and operational functions centralized and reporting to the President, for the primary purpose of achieving scalability in business operations to support the growth in the Company’s strategic markets. Corporate functions and the President report to the CEO. As a result, the Company operates under one operating segment and reports under one reportable segment.
Fair Value Measurements	Fair Value Measurements
	The Company determines the fair value of its assets and liabilities based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. The Company uses a fair value hierarchy with three levels of inputs, of which the first two are considered observable and the last unobservable, to measure fair value:
	•	Level 1 — Quoted prices in active markets for identical assets or liabilities.
	•	Level 2 — Inputs, other than Level 1, that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	•	Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The carrying amounts of financial instruments such as cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable, and accrued liabilities, excluding acquisition related contingent consideration liabilities, approximate the related fair values due to the short-term maturities of these instruments.
Functional Currency	Functional Currency
	The U.S. dollar is the functional currency of the Company’s international operations. The Company remeasures its foreign subsidiaries’ monetary assets and liabilities to the U.S. dollar and records the net gains or losses resulting from remeasurement in other expense, net in the consolidated statements of income.
Acquisitions	Acquisitions
	The Company measures all assets acquired and liabilities assumed, including contingent considerations and all contractual contingencies, at fair value as of the acquisition date. Contingent purchase considerations to be settled in cash are remeasured to estimated fair value at each reporting period with the change in fair value recorded in acquisition related (gain) expense, net, a component of operating expenses. In addition, the Company capitalizes in-process research and development (IPR&D) and either amortizes it over the life of the product upon commercialization, or impairs it if the project is abandoned. Post-acquisition adjustments in deferred tax asset valuation allowances and liabilities for uncertain tax positions are recorded in current period income tax expense.
Cash Equivalents and Short-Term Investments	Cash Equivalents and Short-Term Investments
	Cash equivalents are comprised of short-term, highly liquid investments with maturities of 90 days or less at the date of purchase.
	Short-term investments consist predominantly of debt securities in U.S. government-sponsored entities, corporate debt securities, and U.S. Treasury securities. Management classifies short-term investments as available-for-sale at the time of purchase and evaluates such classification as of each balance sheet date. All short-term investments are recorded at estimated fair value. Unrealized gains and losses for available-for-sale securities are included in accumulated other comprehensive income, a component of stockholders’ equity. The Company evaluates its investments to assess whether those with unrealized loss positions are other than temporarily impaired. Impairments are considered to be other than temporary if they are related to deterioration in credit risk or if it is likely that the Company will sell the securities before the recovery of their cost basis. Realized gains, losses, and declines in value judged to be other than temporary are determined based on the specific identification method and are reported in other (expense) income, net in the consolidated statements of income.
Accounts Receivable	Accounts Receivable
	Trade accounts receivable are recorded at the net invoice value and are not interest bearing. The Company considers receivables past due based on the contractual payment terms. The Company reserves specific receivables if collectibility is no longer reasonably assured. The Company also reserves a percentage of its trade receivable balance based on collection history and current economic trends that might impact the level of future credit losses. The Company re-evaluates such reserves on a regular basis and adjusts its reserves as needed. Once a receivable is deemed to be uncollectible, such balance is charged against the reserve.
Inventory	Inventory
	Inventory is stated at the lower of cost or market, on a first in, first out basis. Inventory includes raw materials and finished goods that may be used in the research and development process and such items are expensed as consumed or expired. Provisions for slow moving, excess, and obsolete inventories are estimated based on product life cycles, quality issues, historical experience, and usage forecasts.
Property and Equipment	Property and Equipment
	Property and equipment are stated at cost, subject to review for impairment, and depreciated over the estimated useful lives of the assets, which generally range from three to seven years, using the straight-line method. Amortization of leasehold improvements is recorded over the shorter of the lease term or the estimated useful life of the related assets. Maintenance and repairs are charged to operations as incurred. When assets are sold, or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts and any gain or loss is included in operating expense.
	In 2013, as a part of the Company’s ongoing effort to upgrade its current information systems, the Company started the implementation of new enterprise resource planning software and applications to manage parts of its business operations. Certain costs incurred in the development of such internal-use software and software applications, including external direct costs of materials and services and applicable compensation costs of employees devoted to specific software development, are capitalized as computer software costs. Costs incurred outside of the application development stage are expensed as incurred.
Leases	Leases
	Leases are reviewed and classified as capital or operating at their inception. The Company records rent expense on a straight-line basis over the term of the lease, which includes the construction build-out period and lease extension periods, if appropriate. The difference between rent payments and straight-line rent expense is recorded as deferred rent in accrued liabilities and other long-term liabilities. Landlord allowances are amortized on a straight-line basis over the lease term as a reduction to rent expense. The Company capitalizes leasehold improvements and amortizes the value over the shorter of the lease term or expected useful lives.
	Headquarter relocation expenses consisted of expenses such as accelerated depreciation expense, impairment of assets, additional rent expense during the transition period in 2012 when both the new and former headquarter facilities were occupied, moving expenses, cease-use losses, and accretion of interest expense on lease exit liability. The Company completed the relocation of its headquarters in 2012 to another facility in San Diego, California and recorded cease-use losses and the corresponding facility exit obligation upon vacating its former headquarters in 2011 and 2012, calculated as the present value of the remaining lease obligation offset by estimated sublease rental receipts during the remaining lease period, adjusted for deferred items and estimated lease incentives. The Company reassesses the facility exit obligation on a quarterly basis and the key assumptions used in the calculation include the amount and timing of estimated sublease rental receipts, and the risk-adjusted discount rate.
Goodwill, Intangible Assets and Other Long-Lived Assets	Goodwill, Intangible Assets and Other Long-Lived Assets
	Goodwill, which has an indefinite useful life, represents the excess of cost over fair value of net assets acquired. The change in the carrying value of goodwill during the year ended December 28, 2014 was due to a current year acquisition and adjustments to the purchase price subsequent to the preliminary allocation of purchase price related to prior year acquisitions. Goodwill is reviewed for impairment at least annually during the second quarter, or more frequently if an event occurs indicating the potential for impairment. During its goodwill impairment review, the Company may assess qualitative factors to determine whether it is more likely than not that the fair value of its reporting unit is less than its carrying amount, including goodwill. The qualitative factors include, but are not limited to, macroeconomic conditions, industry and market considerations, and the overall financial performance of the Company. If, after assessing the totality of these qualitative factors, the Company determines that it is not more likely than not that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company proceeds to perform the two-step test for goodwill impairment. The first step involves comparing the estimated fair value of the reporting unit with its carrying value, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, the Company performs the second step of the goodwill impairment test to determine the amount of loss, which involves comparing the implied fair value of the goodwill to the carrying value of the goodwill. The Company may also elect to bypass the qualitative assessment in a period and elect to proceed to perform the first step of the goodwill impairment test. The Company performed its annual assessment for goodwill impairment in the second quarter of 2014, noting no impairment.
	The Company’s identifiable intangible assets are typically comprised of acquired core technologies, licensed technologies, customer relationships, license agreements, and trade names. The cost of identifiable intangible assets with finite lives is generally amortized on a straight-line basis over the assets’ respective estimated useful lives.
	The Company regularly performs reviews to determine if any event has occurred that may indicate its intangible assets with finite useful lives and other long-lived assets are potentially impaired. If indicators of impairment exist, the Company performs an impairment test to assess the recoverability of the affected assets by determining whether the carrying amount of such assets exceeds the undiscounted expected future cash flows. If the affected assets are not recoverable, the Company estimates the fair value of the assets and records an impairment loss if the carrying value of the assets exceeds the fair value. Factors that may indicate potential impairment include a significant decline in the Company’s stock price and market capitalization compared to its net book value, significant changes in the ability of a particular asset to generate positive cash flows the Company’s strategic business objectives, and the pattern of utilization of a particular asset.
	During 2013, the Company decided to discontinue its Eco and NuPCR product lines to better align its product portfolio with its core strategy. As a result, the Company recorded a total impairment charge of $25.2 million in cost of product revenue, $22.9 million of which related to identifiable intangible assets.
Derivatives	Derivatives
	The Company is exposed to foreign exchange rate risks in the normal course of business. The Company enters into foreign exchange contracts to manage foreign currency risks related to monetary assets and liabilities that are denominated in currencies other than the U.S. dollar. These foreign exchange contracts are carried at fair value in other assets or other liabilities and are not designated as hedging instruments. Changes in the value of the derivatives are recognized in other expense, net, along with the remeasurement gain or loss on the foreign currency denominated assets or liabilities.
	As of December 28, 2014, the Company had foreign exchange forward contracts in place to hedge exposures in the euro, Japanese yen, and Australian dollar. As of December 28, 2014 and December 29, 2013, the total notional amount of outstanding forward contracts in place for foreign currency purchases was $61.0 million and $54.7 million, respectively. Non-designated foreign exchange forward contract related gain was $4.1 million and $3.5 million for the years ended December 28, 2014 and December 29, 2013, respectively, and immaterial for the year ended December 30, 2012.
Reserve for Product Warranties	Reserve for Product Warranties
	The Company generally provides a one-year warranty on instruments. Additionally, the Company provides a warranty on consumables through the expiration date, which generally ranges from six to twelve months after the manufacture date. At the time revenue is recognized, the Company establishes an accrual for estimated warranty expenses based on historical experience as well as anticipated product performance. The Company periodically reviews its warranty reserve for adequacy and adjusts the warranty accrual, if necessary, based on actual experience and estimated costs to be incurred. Warranty expense is recorded as a component of cost of product revenue.
Revenue Recognition	Revenue Recognition
	The Company’s revenue is generated primarily from the sale of products and services. Product revenue primarily consists of sales of instruments and consumables used in genetic analysis. Service and other revenue primarily consists of revenue generated from genotyping and sequencing services and instrument service contracts.
	The Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the seller’s price to the buyer is fixed or determinable, and collectibility is reasonably assured. In instances where final acceptance of the product or system is required, revenue is deferred until all the acceptance criteria have been met. The Company occasionally offers discounts on newly introduced products to recent customers or existing products. These promotions sometimes involve the trade-in of existing products in exchange for a discount on new products. Where applicable, the Company defers a portion of revenue on the sales of existing products in recognition of the promotional discounts until the delivery of new products. All revenue is recorded net of discounts and sales taxes collected on behalf of governmental authorities.
	Revenue from product sales is recognized generally upon transfer of title to the customer, provided that no significant obligations remain and collection of the receivable is reasonably assured. Revenue from instrument service contracts is recognized as the services are rendered, typically evenly over the contract term. Revenue from genotyping and sequencing services is recognized when earned, which is generally at the time the genotyping or sequencing analysis data is made available to the customer or agreed upon milestones are reached.
	In order to assess whether the price is fixed or determinable, the Company evaluates whether an arrangement is cancellable or subject to future changes in price, deliverables, or other terms. If it is determined that the price is not fixed or determinable, the Company defers revenue recognition until the price becomes fixed or determinable. The Company assesses collectibility based on a number of factors, including past transaction history with, and the creditworthiness of, the customer. If the Company determines that collection of a payment is not reasonably assured, revenue recognition is deferred until receipt of payment.
	The Company regularly enters into contracts where revenue is derived from multiple deliverables including products or services. These products or services are generally delivered within a short time frame, approximately three to six months, after the contract execution date. Revenue recognition for contracts with multiple deliverables is based on the individual units of accounting determined to exist in the contract. A delivered item is considered a separate unit of accounting when the delivered item has value to the customer on a stand-alone basis. Items are considered to have stand-alone value when they are sold separately by any vendor or when the customer could resell the item on a stand-alone basis.
	For transactions with multiple deliverables, consideration is allocated at the inception of the contract to all deliverables based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence (VSOE) of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence exists, the Company uses its best estimate of the selling price for the deliverable.
	In order to establish VSOE of selling price, the Company must regularly sell the product or service on a standalone basis with a substantial majority priced within a relatively narrow range. VSOE of selling price is usually the midpoint of that range. If there are not a sufficient number of standalone sales and VSOE of selling price cannot be determined, then the Company considers whether third party evidence can be used to establish selling price. Due to the lack of similar products and services sold by other companies within the industry, the Company has rarely established selling price using third-party evidence. If neither VSOE nor third party evidence of selling price exists, the Company determines its best estimate of selling price using average selling prices over a rolling 12-month period coupled with an assessment of current market conditions. If the product or service has no history of sales or if the sales volume is not sufficient, the Company relies upon prices set by the Company’s pricing committee adjusted for applicable discounts. The Company recognizes revenue for delivered elements only when it determines there are no uncertainties regarding customer acceptance.
	In certain markets, the Company sells products and provides services to customers through distributors that specialize in life science products. In most sales through distributors, the product is delivered directly to customers. In cases where the product is delivered to a distributor, revenue recognition is deferred until acceptance is received from the distributor, and/or the end-user, if required by the applicable sales contract. The terms of sales transactions through distributors are consistent with the terms of direct sales to customers. These transactions are accounted for in accordance with the Company’s revenue recognition policy described herein.
Share-Based Compensation	Share-Based Compensation
	The Company incurs share-based compensation expense related to restricted stock, its Employee Stock purchase Plan (ESPP), and stock options.
	Restricted stock units (RSU), restricted stock awards (RSA), and performance stock units (PSU) are all considered restricted stock. The fair value of restricted stock is determined by the closing market price of the Company’s common stock on the date of grant. The Company recognizes share-based compensation expense based on the fair value on a straight-line basis over the requisite service periods of the awards, taking into consideration estimated forfeitures. PSU represents a right to receive a certain number of shares of common stock based on the achievement of corporate performance goals and continued employment during the vesting period. At each reporting period, the Company reassesses the probability of the achievement of such corporate performance goals and any additional expenses resulting from an adjustment in the estimated shares to be released are treated as a cumulative catch-up in the period of adjustment.
	The Company uses the Black-Scholes-Merton option-pricing model to estimate the fair value of stock purchases under ESPP and stock options granted. The model assumptions include expected volatility, term, dividends, and the risk-free interest rate. The Company determines the expected volatility by equally weighing the historical and implied volatility of the Company’s common stock. The historical volatility is generally commensurate with the estimated expected term of the Company’s stock awards, adjusted for the impact of unusual fluctuations and other relevant factors. The implied volatility is calculated from the implied market volatility of exchange-traded call options on the Company’s common stock. The expected term of an award is based on historical forfeiture experience, exercise activity, and on the terms and conditions of the stock awards. The expected dividend yield is determined to be 0% given that the Company has never declared or paid cash dividends on its common stock and does not anticipate paying such cash dividends. The risk-free interest rate is based upon U.S. Treasury securities with remaining terms similar to the expected term of the share-based awards.
Shipping and Handling Expenses	Shipping and Handling Expenses
	Shipping and handling expenses are included in cost of product revenue.
Research and Development	Research and Development
	Research and development expenses include personnel expenses, contractor fees, license fees, facilities costs, and utilities. Expenditures relating to research and development are expensed in the period incurred.
Advertising Costs	Advertising Costs
	The Company expenses advertising costs as incurred. Advertising costs were $16.4 million, $14.5 million, and $10.5 million for the years ended December 28, 2014, December 29, 2013, and December 30, 2012, respectively.
Income Taxes	Income Taxes
	The provision for income taxes is computed using the asset and liability method, under which deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities, and for the expected future tax benefit to be derived from tax loss and credit carryforwards. Deferred tax assets and liabilities are determined using the enacted tax rates in effect for the years in which those tax assets are expected to be realized. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date.
	Deferred tax assets are regularly assessed to determine the likelihood they will be recovered from future taxable income. A valuation allowance is established when the Company believes it is more likely than not the future realization of all or some of a deferred tax asset will not be achieved. In evaluating the ability to recover deferred tax assets within the jurisdiction which they arise the Company considers all available positive and negative evidence. Factors reviewed include the cumulative pre-tax book income for the past three years, scheduled reversals of deferred tax liabilities, history of earnings and reliable forecasting, projections of pre-tax book income over the foreseeable future, and the impact of any feasible and prudent tax planning strategies.
	The Company recognizes excess tax benefits associated with share-based compensation to stockholders’ equity only when realized. When assessing whether excess tax benefits relating to share-based compensation have been realized, the Company follows the with-and-without approach excluding any indirect effects of the excess tax deductions. Under this approach, excess tax benefits related to share-based compensation are not deemed to be realized until after the utilization of all other tax benefits available to the Company.
	The Company recognizes the impact of a tax position in the financial statements only if that position is more likely than not of being sustained upon examination by taxing authorities, based on the technical merits of the position. Any interest and penalties related to uncertain tax positions will be reflected in income tax expense.
Net Income per Share	Net Income per Share
	Basic net income per share is computed based on the weighted average number of common shares outstanding during the period. Diluted net income per share is computed based on the sum of the weighted average number of common shares and potentially dilutive common shares outstanding during the period.
	Potentially dilutive common shares consist of shares issuable under convertible senior notes, equity awards, and warrants. Convertible senior notes have a dilutive impact when the average market price of the Company’s common stock exceeds the applicable conversion price of the respective notes. Potentially dilutive common shares from equity awards and warrants are determined using the average share price for each period under the treasury stock method. In addition, the following amounts are assumed to be used to repurchase shares: proceeds from exercise of equity awards and warrants; the average amount of unrecognized compensation expense for equity awards; and estimated tax benefits that will be recorded in additional paid-in capital when expenses related to equity awards become deductible. In loss periods, basic net loss per share and diluted net loss per share are identical because the otherwise dilutive potential common shares become anti-dilutive and are therefore excluded.
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income
	Comprehensive income is comprised of net income and other comprehensive income. Accumulated other comprehensive income on the consolidated balance sheets at December 28, 2014 and December 29, 2013 includes accumulated foreign currency translation adjustments and unrealized gains and losses on the Company’s available-for-sale securities.

Organization_and_Summary_of_Si2

Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 28, 2014
Accounting Policies [Abstract]
Weighted-average shares used to calculate basic and diluted net income per share	The following table presents the calculation of weighted average shares used to calculate basic and diluted net income per share (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Weighted average shares outstanding	135,553			125,076			122,999
	Effect of potentially dilutive common shares from:
	Convertible senior notes	3,489			1,340			967
	Equity awards	4,340			4,404			3,906
	Warrants	5,595			9,116			5,821
	Weighted average shares used in calculating diluted net income per share	148,977			139,936			133,693
	Potentially dilutive shares excluded from calculation due to anti-dilutive effect	124			996			2,556
Accumulated other comprehensive income	The components of accumulated other comprehensive income are as follows (in thousands):
		December 28,				December 29,
		2014				2013
	Foreign currency translation adjustments	$	1,289			$	1,289
	Unrealized loss on available-for-sale securities, net of deferred tax	(2,369		)		(55		)
	Total accumulated other comprehensive income	$	(1,080	)		$	1,234

Balance_Sheet_Account_Details_

Balance Sheet Account Details (Tables)	12 Months Ended
	Dec. 28, 2014
Balance Sheet Account Details [Abstract]
Short-term Investments	The following is a summary of short-term investments (in thousands):
		December 28, 2014												December 29, 2013
					Gross			Gross								Gross		Gross
		Amortized			Unrealized			Unrealized			Estimated			Amortized		Unrealized		Unrealized			Estimated
		Cost			Gains			Losses			Fair Value			Cost		Gains		Losses			Fair Value
	Available-for-sale securities:
	Debt securities in government-sponsored entities	$	51,308		$	10		$	(55	)	$	51,263		$	82,226	$	18	$	(101	)	$	82,143
	Corporate debt securities	502,924			46			(2,882		)	500,088			342,034		312		(376		)	341,970
	U.S. Treasury securities	151,255			5			(394		)	150,866			29,795		58		—			29,853
	Total available-for-sale securities	$	705,487		$	61		$	(3,331	)	$	702,217		$	454,055	$	388	$	(477	)	$	453,966
Available-for-sale securities in unrealized loss positions	The following table shows the estimated fair values and the gross unrealized losses of the Company’s available-for-sale securities that were in an unrealized loss position for less than twelve months as of December 28, 2014 and December 29, 2013, aggregated by investment category (in thousands):
		December 28, 2014						December 29, 2013
		Estimated			Gross			Estimated			Gross
		Fair Value			Unrealized			Fair Value			Unrealized
					Losses						Losses
	Debt securities in government-sponsored entities	$	36,084		$	(55	)	$	73,362		$	(101	)
	Corporate debt securities	428,078			(2,882		)	168,118			(373		)
	U.S. Treasury securities	143,755			(394		)	—			—
	Total	$	607,917		$	(3,331	)	$	241,480		$	(474	)
Contractual maturities of available-for-sale securities	Contractual maturities of available-for-sale debt securities as of December 28, 2014 are as follows (in thousands):
		Estimated Fair Value
	Due within one year	$	238,198
	After one but within five years	464,019
	Total	$	702,217
Accounts receivable	Accounts receivable, net consist of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Accounts receivable from product and service sales	$	292,847		$	241,360
	Other receivables	2,070			1,266
	Total accounts receivable, gross	294,917			242,626
	Allowance for doubtful accounts	(5,459		)	(3,680		)
	Total accounts receivable, net	$	289,458		$	238,946
Inventory	Inventory consists of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Raw materials	$	70,316		$	57,398
	Work in process	94,102			70,016
	Finished goods	26,726			26,685
	Total inventory	$	191,144		$	154,099
Property and equipment	Property and equipment, net consists of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Leasehold improvements	$	143,597		$	104,571
	Machinery and equipment	192,715			175,340
	Computer hardware and software	86,929			73,544
	Furniture and fixtures	13,669			10,511
	Building	7,670			7,670
	Construction in progress	35,421			8,531
	Total property and equipment, gross	480,001			380,167
	Accumulated depreciation	(214,737		)	(177,501		)
	Total property and equipment, net	$	265,264		$	202,666
Goodwill	Changes to the Company’s goodwill balance during the year ended December 28, 2014 and December 29, 2013 are as follows (in thousands):
		28-Dec-14			29-Dec-13
	Balance at beginning of period	$	723,061		$	369,327
	Current period acquisition	3,338			353,734
	Purchase price allocation adjustments related to prior year acquisitions	(1,495		)	—
	Balance at end of period	$	724,904		$	723,061
Accrued liabilities	Accrued liabilities consist of the following (in thousands):
		December 28,			December 29,
		2014			2013
	Accrued compensation expenses	$	112,606		$	82,705
	Deferred revenue, current portion	75,294			50,834
	Acquisition related contingent consideration liability, current portion	44,124			6,719
	Accrued taxes payable	38,942			30,435
	Customer deposits	20,274			13,569
	Reserve for product warranties	15,616			10,407
	Facility exit obligation, current portion	3,837			5,570
	Other	24,583			18,881
	Total accrued liabilities	$	335,276		$	219,120

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 28, 2014
Business Combinations [Abstract]
Allocation of the purchase price to the assets acquired and liabilities assumed	As of December 29, 2013, the allocation of the purchase price to the assets acquired and liabilities assumed on the acquisition date was as follows (in thousands):
		Allocation of purchase price
	Cash and cash equivalents	$	9,151
	Accounts receivable	2,801
	Inventory	1,110
	Prepaid expenses and other current assets	979
	Property and equipment	12,083
	Other assets	978
	Intangible assets	176,490
	Goodwill	227,453
	Accounts payable	(2,539		)
	Accrued liabilities	(3,803		)
	Lease financing obligation	(9,695		)
	Deferred tax liability	(18,741		)
	Total purchase price	$	396,267
Fair value of identifiable intangible assets acquired	The following table summarizes the fair value of identifiable intangible assets acquired (amounts in thousands):
		Weighted Average Useful Lives		Fair Value
		(in years)
	Developed technology	13		$	170,200
	Customer relationships	5		4,690
	Trade name	2		1,600
	Total intangible assets acquired, excluding goodwill			$	176,490
Pro forma information	The following unaudited pro forma information presents the consolidated results of operations of the Company as if the acquisitions completed during the year ended December 29, 2013 had occurred at the beginning of the applicable annual reporting period, with pro forma adjustments to give effect to intercompany transactions to be eliminated, amortization of intangible assets, share-based compensation, and transaction costs directly associated with the acquisitions (in thousands, except per share amounts):
		Years Ended
		December 29,				December 30,
		2013				2012
	Net revenues	$	1,433,935			$	1,161,241
	Net income	$	113,869			$	92,645
	Net income per share-basic	$	0.91			$	0.75
	Net income per share-diluted	$	0.81			$	0.69
Contingent compensation expense	Contingent compensation expenses recorded as a result of acquisitions consist of the following (in thousands):
		Years Ended
		December 28,				December 29,		December 30,
		2014				2013		2012
	Contingent compensation expense, included in research and development expense	$	1,509			$	544	$	3,419
	Contingent compensation expense, included in selling, general and administrative expense	2,756				13,066		5,732
	Total contingent compensation expense	$	4,265			$	13,610	$	9,151

Intangible_Assets_Tables

Intangible Assets (Tables)	12 Months Ended
	Dec. 28, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Identifiable intangible assets	The following is a summary of the Company’s identifiable intangible assets (in thousands):
		December 28, 2014									December 29, 2013
		Gross				Accumulated			Intangibles,		Gross		Accumulated			Intangibles,
		Carrying				Amortization			Net		Carrying		Amortization			Net
		Amount									Amount
	Licensed technologies	$	83,956			$	(39,423	)	$	44,533	$	48,361	$	(31,927	)	$	16,434
	Core technologies	321,200				(77,493		)	243,707		321,700		(45,534		)	276,166
	Customer relationships	26,461				(12,522		)	13,939		26,770		(7,376		)	19,394
	License agreements	15,042				(4,592		)	10,450		18,917		(4,947		)	13,970
	Trade name	4,700				(2,829		)	1,871		11,800		(6,591		)	5,209
	Total intangible assets, net	$	451,359			$	(136,859	)	$	314,500	$	427,548	$	(96,375	)	$	331,173
Acquired intangible assets	Intangible assets acquired during the year ended December 28, 2014 are as follows (in thousands):
		Weighted-Average		Gross
		Useful Lives		Carrying
		(in years)		Amount
	Licensed technologies	4.7		$	35,595
	Customer relationships	0.5		291
	License agreements	7.2		125
	Total intangible asset additions			$	36,011
Estimated annual amortization of intangible assets	The estimated annual amortization of intangible assets for the next five years and thereafter is shown in the following table (in thousands). Actual amortization expense to be reported in future periods could differ from these estimates as a result of acquisitions, divestitures, asset impairments, among other factors.
		Estimated Annual Amortization
	2015	$	52,994
	2016	47,752
	2017	43,276
	2018	33,971
	2019	30,685
	Thereafter	105,822
	Total	$	314,500

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 28, 2014
Fair Value Disclosures [Abstract]
Fair value measurements	The following table presents the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of December 28, 2014 and December 29, 2013 (in thousands):
		December 28, 2014									December 29, 2013
		Level 1			Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Assets:
	Money market funds (cash equivalent)	$	431,172		$	—	$	—	$	431,172	$	478,755	$	—	$	—	$	478,755
	Debt securities in government-sponsored entities	—			51,263		—		51,263		—		82,143		—		82,143
	Corporate debt securities	—			500,088		—		500,088		—		341,970		—		341,970
	U.S. Treasury securities	150,866			—		—		150,866		29,853		—		—		29,853
	Deferred compensation plan assets	—			23,486		—		23,486		—		17,805		—		17,805
	Total assets measured at fair value	$	582,038		$	574,837	$	—	$	1,156,875	$	508,608	$	441,918	$	—	$	950,526
	Liabilities:
	Acquisition related contingent consideration liabilities	$	—		$	—	$	44,124	$	44,124	$	—	$	—	$	49,480	$	49,480
	Deferred compensation liability	—			20,310		—		20,310		—		14,957		—		14,957
	Total liabilities measured at fair value	$	—		$	20,310	$	44,124	$	64,434	$	—	$	14,957	$	49,480	$	64,437
Changes in estimated fair value of contingent consideration liabilities	Changes in estimated fair value of contingent consideration liabilities from January 1, 2012 through December 28, 2014 are as follows (in thousands):
		Contingent
		Consideration
		Liability
		(Level 3
		Measurement)
	Balance as of January 1, 2012	$	6,638
	Acquisition of BlueGnome	7,500
	Change in estimated fair value, recorded in acquisition related (gain) expense, net	1,975
	Cash payments	(3,594		)
	Balance as of December 30, 2012	12,519
	Additional liability recorded for current period acquisitions	60,184
	Change in estimated fair value, recorded in acquisition related (gain) expense, net	(18,784		)
	Cash payments	(4,439		)
	Balance as of December 29, 2013	49,480
	Change in estimated fair value, recorded in acquisition related (gain) expense, net	(5,356		)
	Balance as of December 28, 2014	$	44,124

Convertible_Senior_Notes_Table

Convertible Senior Notes (Tables)	12 Months Ended
	Dec. 28, 2014
Debt Disclosure [Abstract]
Schedule of Extinguishment of Debt	The following table summarizes information about the conversion of the 2014 Notes during the year ended December 28, 2014 (in thousands):
		2014 Notes
	Cash paid for principal of notes converted	$	29,570
	Conversion value over principal amount paid in shares of common stock	$	196,095
	Number of shares of common stock issued upon conversion	1,151
Summarized information about equity and liability components of convertible senior notes	The following table summarizes information about the equity and liability components of all convertible senior notes outstanding as of the period reported (dollars in thousands). The fair values of the respective notes outstanding were measured based on quoted market prices.
		December 28,			December 29, 2013
		2014
	Principal amount of convertible notes outstanding	$	1,470,027		$	949,570
	Unamortized discount of liability component	(178,991		)	(80,977		)
	Net carrying amount of liability component	1,291,036			868,593
	Less: current portion	(304,256		)	(29,288		)
	Long-term debt	$	986,780		$	839,305
	Conversion option subject to cash settlement	—			$	282
	Carrying value of equity component, net of issuance costs	$	215,283		$	274,304
	Fair value of outstanding notes	$	2,021,750		$	1,428,743
	Weighted average remaining amortization period of discount on the liability component	5.2 years			2.2 years

Commitments_Tables

Commitments (Tables)	12 Months Ended
	Dec. 28, 2014
Commitments and Contingencies Disclosure [Abstract]
Future minimum payments under operating leases	Annual future minimum payments under operating leases as of December 28, 2014 were as follows (in thousands):
		Operating			Sublease			Net Operating
		Leases			Income			Leases
	2015	$	35,210		$	(2,900	)	$	32,310
	2016	38,892			(2,924		)	35,968
	2017	37,064			(2,708		)	34,356
	2018	37,747			(2,789		)	34,958
	2019	39,656			(2,873		)	36,783
	Thereafter	415,052			(11,837		)	403,215
	Total minimum lease payments	$	603,621		$	(26,031	)	$	577,590
Facility exit obligations	Changes in the facility exit obligation from January 1, 2012 through December 28, 2014 are as follows (in thousands):
		Facility Exit Obligation
	Balance as of January 1, 2012:	$	25,049
	Adjustment to facility exit obligation	24,878
	Accretion of interest expense	2,129
	Cash payments	(6,704		)
	Balance as of December 30, 2012	45,352
	Adjustment to facility exit obligation	(114		)
	Accretion of interest expense	2,738
	Cash payments	(9,758		)
	Balance as of December 29, 2013	38,218
	Adjustment to facility exit obligation	2,555
	Accretion of interest expense	2,638
	Cash payments	(5,711		)
	Balance as of December 28, 2014	$	37,700
Annual future minimum royalty payments	Annual future minimum royalty payments under the Company’s licensing agreements as of December 28, 2014 are as follows (in thousands):
		Minimum Payments
	2015	$	8,650
	2016	12,470
	2017	13,500
	2018	18,475
	2019	23,480
	Thereafter	23,550
	Total minimum royalty payments	$	100,125
Reserve for product warranties	Changes in the Company’s reserve for product warranties from January 1, 2012 through December 28, 2014 are as follows (in thousands):
		Warranty Reserve
	Balance as of January 1, 2012	$	11,966
	Additions charged to cost of revenue	17,279
	Repairs and replacements	(19,109		)
	Balance as of December 30, 2012	10,136
	Additions charged to cost of revenue	15,674
	Repairs and replacements	(15,403		)
	Balance as of December 29, 2013	10,407
	Additions charged to cost of revenue	24,150
	Repairs and replacements	(18,941		)
	Balance as of December 28, 2014	$	15,616

Sharebased_Compensation_Expens1

Share-based Compensation Expense (Tables)	12 Months Ended
	Dec. 28, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense for all stock awards	Share-based compensation expense for all stock awards consists of the following (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Cost of product revenue	$	9,451		$	6,223		$	7,575
	Cost of service and other revenue	1,204			777			461
	Research and development	50,880			37,439			30,879
	Selling, general and administrative	91,016			61,387			55,409
	Share-based compensation expense before taxes	152,551			105,826			94,324
	Related income tax benefits	(44,194		)	(32,819		)	(30,759		)
	Share-based compensation expense, net of taxes	$	108,357		$	73,007		$	63,565
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted	The assumptions used for the specified reporting periods and the resulting estimates of weighted-average grant date fair value per share of options granted and for stock purchased under the ESPP are as follows:
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Stock options granted:
	Risk-free interest rate	—			0.14 - 1.86%			0.56 - 0.93%
	Expected volatility	—			30 - 44%			41 - 48%
	Expected term	—			0.8 - 9.4 years			4.0 - 6.6 years
	Expected dividends	—			—			—
	Weighted-average grant-date fair value per share	—			$	40.66		$	15.47
	Stock purchased under the ESPP:
	Risk-free interest rate	0.05 - 0.13%			0.08 - 0.15%			0.09 - 0.17%
	Expected volatility	38% - 41%			31 - 32%			33 - 64%
	Expected term	0.5 - 1.0 year			0.5 - 1.0 year			0.5 - 1.0 year
	Expected dividends	—			—			—
	Weighted-average grant-date fair value per share	$	44.64		$	19.3		$	16.45

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 28, 2014
Equity [Abstract]
Stock option activity under all stock option plans	The Company’s stock option activity under all stock option plans from January 1, 2012 through December 28, 2014 is as follows:
		Options		Weighted-
		(in thousands)		Average
				Exercise Price
	Outstanding at January 1, 2012	10,378		$	29.69
	Granted	251		$	40.79
	Exercised	(2,071	)	$	20.34
	Cancelled	(207	)	$	39.18
	Outstanding at December 30, 2012	8,351		$	32.1
	Granted	512		$	14.74
	Exercised	(3,006	)	$	27.7
	Cancelled	(133	)	$	41.8
	Outstanding at December 29, 2013	5,724		$	32.64
	Exercised	(2,478	)	$	29.93
	Cancelled	(35	)	$	31.73
	Outstanding at December 28, 2014	3,211		$	34.74
Restricted stock activity	A summary of the Company’s restricted stock activity and related information from January 1, 2012 through December 28, 2014 is as follows (in thousands, except per share amounts):
		Restricted		Restricted			Performance			Weighted-Average
		Stock Awards		Stock Units			Stock Units			Grant-Date Fair Value per Share
		(RSA)		(RSU)			(PSU)			RSA		RSU		PSU
	Outstanding at January 1, 2012	230		3,476			—			$	65.95	$	41.87	—
	Awarded	312		1,640			599			$	47.91	$	48.52	$	49.66
	Vested	(77	)	(1,062	)		—			$	65.95	$	38.48	—
	Cancelled	—		(394	)		(12	)		—		$	45.05	$	50.54
	Outstanding at December 30, 2012	465		3,660			587			$	53.84	$	45.49	$	49.64
	Awarded	—		1,532			584			—		$	77.53	$	59.16
	Vested	(217	)	(1,308	)		—			$	54.27	$	42.97	—
	Cancelled	—		(256	)		(70	)		—		$	49.24	$	50.42
	Outstanding at December 29, 2013	248		3,628			1,101			$	53.46	$	59.66	$	54.64
	Awarded	—		780			968			—		$	172.53	$	104.52
	Vested	(140	)	(1,383	)		(753	)		$	47.9	$	55.44	$	49.52
	Cancelled	—		(184	)		(59	)		—		$	65.09	$	52.87
	Outstanding at December 28, 2014	108		2,841			1,257			$	56.62	$	92.35	$	96.21
Pre-tax intrinsic values of all outstanding restricted stock and total fair values of vested restricted stock	Pre-tax intrinsic values and total fair value of vested restricted stock are as follows (in thousands):
		Years Ended
		December 28,			December 29,				December 30,
		2014			2013				2012
	Pre-tax intrinsic value of outstanding restricted stock:
	RSA	$	20,321		$	27,384			$	25,437
	RSU	$	534,708		$	400,421			$	200,383
	PSU	$	236,606		$	121,555			$	32,149
	Fair value of restricted stock vested:
	RSA	$	6,712		$	11,750			$	5,039
	RSU	$	76,646		$	56,212			$	40,870
	PSU	$	37,313		—				—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 28, 2014
Income Tax Disclosure [Abstract]
Income before income taxes summarized by region	The income before income taxes summarized by region is as follows (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	United States	$	176,974		$	(53,703	)	$	102,296
	Foreign	271,784			213,017			120,312
	Total income before income taxes	$	448,758		$	159,314		$	222,608
Provision for income taxes	The provision for income taxes consists of the following (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Current:
	Federal	$	60,984		$	78,419		$	57,285
	State	12,381			8,854			10,121
	Foreign	41,815			39,416			31,504
	Total current provision	115,180			126,689			98,910
	Deferred:
	Federal	(3,191		)	(69,102		)	(7,724		)
	State	(4,974		)	(15,222		)	(7,708		)
	Foreign	(11,608		)	(8,359		)	(12,124		)
	Total deferred benefit	(19,773		)	(92,683		)	(27,556		)
	Total tax provision	$	95,407		$	34,006		$	71,354
Provision for income taxes reconciles to the amount computed by applying the federal statutory rate to income before taxes	The provision for income taxes reconciles to the amount computed by applying the federal statutory rate to income before taxes as follows (in thousands):
		Years Ended
		December 28,			December 29,			December 30,
		2014			2013			2012
	Tax at federal statutory rate	$	157,065		$	55,760		$	77,913
	State, net of federal benefit	5,023			647			4,056
	Research and other credits	(16,144		)	(10,977		)	(2,613		)
	Change in valuation allowance	(4,212		)	10,544			(37		)
	Change in fair value of contingent consideration	(1,321		)	(3,859		)	—
	Impact of foreign operations	(42,215		)	(18,006		)	(11,470		)
	Other	(2,789		)	(103		)	3,505
	Total tax provision	$	95,407		$	34,006		$	71,354
Significant components of deferred tax assets and liabilities	Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):
		December 28,			December 29,
		2014			2013
	Deferred tax assets:
	Net operating losses	$	47,738		$	66,969
	Tax credits	32,192			36,277
	Other accruals and reserves	41,676			86,716
	Stock compensation	54,570			36,728
	Deferred rent	25,975			16,823
	Inventory adjustments	12,003			9,034
	Other amortization	28,203			9,571
	Other	24,045			18,244
	Total gross deferred tax assets	266,402			280,362
	Valuation allowance on deferred tax assets	(15,191		)	(19,132		)
	Total deferred tax assets	251,211			261,230
	Deferred tax liabilities:
	Purchased intangible amortization	(85,612		)	(98,671		)
	Convertible debt	(61,383		)	(27,821		)
	Property and equipment	(16,521		)	(13,311		)
	Other	(1,670		)	(6,349		)
	Total deferred tax liabilities	(165,186		)	(146,152		)
	Net deferred tax assets	$	86,025		$	115,078
Summary of the gross amount of uncertain tax positions	The following table summarizes the gross amount of the Company’s uncertain tax positions (in thousands):
		December 28,			December 29,			December 30,
		2014			2013			2012
	Balance at beginning of year	$	49,046		$	37,585		$	28,396
	Increases related to prior year tax positions	426			4,794			2,573
	Decreases related to prior year tax positions	(804		)	(223		)	(69		)
	Increases related to current year tax positions	8,756			7,503			6,685
	Decreases related to lapse of statute of limitations	(5,336		)	(613		)	—
	Balance at end of year	$	52,088		$	49,046		$	37,585

Segment_Information_Geographic1

Segment Information, Geographic Data, and Significant Customers (Tables)	12 Months Ended
	Dec. 28, 2014
Segment Reporting [Abstract]
Revenue by region	The Company had revenue in the following regions for the years ended December 28, 2014, December 29, 2013, and December 30, 2012 (in thousands):
		Years Ended
		December 28,		December 29,		December 30,
		2014		2013		2012
	United States	$	950,703	$	714,662	$	568,443
	Europe	466,536		354,682		291,404
	Asia-Pacific	342,702		276,442		232,498
	Other markets	101,417		75,392		56,171
	Total	$	1,861,358	$	1,421,178	$	1,148,516
Net long-lived assets consisting of property and equipment by region	The Company had net long-lived assets consisting of property and equipment in the following regions as of December 28, 2014 and December 29, 2013 (in thousands):
		December 28,		December 29,
		2014		2013
	United States	$	204,717	$	150,470
	United Kingdom	31,965		24,122
	Singapore	22,326		21,311
	Other countries	6,256		6,763
	Total	$	265,264	$	202,666

Quarterly_Financial_Informatio1

Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 28, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	Summarized quarterly data for fiscal years 2014 and 2013 are as follows (in thousands, except per share amounts):
		First Quarter			Second Quarter		Third Quarter		Fourth Quarter
	2014
	Total revenue	$	420,781		$	447,568	$	480,630	$	512,379
	Gross profit	$	278,292		$	300,540	$	333,941	$	384,937
	Net income	$	59,977		$	46,605	$	93,489	$	153,280
	Net income per share, basic	$	0.47		$	0.36	$	0.66	$	1.08
	Net income per share, diluted	$	0.4		$	0.31	$	0.63	$	1.03
	2013
	Total revenue	$	330,958		$	346,094	$	356,800	$	387,326
	Gross profit	$	219,292		$	223,409	$	209,940	$	259,246
	Net (loss) income	$	(22,587	)	$	35,877	$	31,357	$	80,661
	Net (loss) income per share, basic	$	(0.18	)	$	0.29	$	0.25	$	0.64
	Net (loss) income per share, diluted	$	(0.18	)	$	0.26	$	0.22	$	0.56

Organization_and_Summary_of_Si3

Organization and Summary of Significant Accounting Policies (Details)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Weighted average shares used to calculate basic and diluted net income per share [Line Items]
Weighted average shares outstanding	135,553	125,076	122,999
Convertible senior notes	3,489	1,340	967
Equity awards	4,340	4,404	3,906
Warrants	5,595	9,116	5,821
Weighted average shares used in calculating diluted net income per share	148,977	139,936	133,693
Potentially dilutive shares excluded from calculation due to anti-dilutive effect	124	996	2,556

Organization_and_Summary_of_Si4

Organization and Summary of Significant Accounting Policies (Details 1) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Accounting Policies [Abstract]
Foreign currency translation adjustments	$1,289	$1,289
Unrealized loss on available-for-sale securities, net of deferred tax	-2,369	-55
Total accumulated other comprehensive income	($1,080)	$1,234

Organization_and_Summary_of_Si5

Organization and Summary of Significant Accounting Policies (Details Textual) (USD $)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
	segments
Operating Cycle	P52W	P52W	P52W
Number of operating segments	1
Number of reportable segments	1
Impairments	($2,000,000)	$25,214,000	$21,438,000
Notional amount of outstanding forward contracts	61,000,000	54,700,000
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	4,100,000	3,500,000
Instrument warranty period	1 year
Period of time average selling prices are observed to establish best estimate of selling price	12 months
Expected dividend yield	0.00%
Advertising expense	16,400,000	14,500,000	10,500,000
Minimum [Member]
Useful life	3 years
Warranty on consumable sales through the expiration date	6 months
Product or service delivery period	3 months
Maximum [Member]
Useful life	7 years
Warranty on consumable sales through the expiration date	12 months
Product or service delivery period	6 months
Cost of Sales [Member]
Impairments		25,214,000
Intangible asset impairments		$22,900,000

Organization_and_Summary_of_Si6

Organization and Summary of Significant Accounting Policies (Details Textual 2)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Concentration Risk [Line Items]
Maximum investment portfolio credit exposure per issuer at time of purchase	5.00%
Maximum investment portfolio credit exposure per total issue size outstanding at time of purchase	5.00%
Maximum investment portfolio credit exposure per industry sector at time of purchase	30.00%
Sales Revenue, Segment [Member] | Countries outside the United States
Concentration Risk [Line Items]
Concentration Risk, Percentage	49.00%	50.00%	51.00%
Accounts Receivable [Member] | Countries outside the United States
Concentration Risk [Line Items]
Concentration Risk, Percentage	48.00%	52.00%

Balance_Sheet_Account_Details_1

Balance Sheet Account Details (Details) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Available-for-sale securities:
Available for sale securities, Amortized Cost	$705,487	$454,055
Total Estimated Fair Value	702,217	453,966
Debt securities in government sponsored entities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	51,308	82,226
Total Estimated Fair Value	51,263	82,143
Corporate debt securities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	502,924	342,034
Total Estimated Fair Value	500,088	341,970
U.S. Treasury securities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	151,255	29,795
Total Estimated Fair Value	$150,866	$29,853

Balance_Sheet_Account_Details_2

Balance Sheet Account Details (Details 1) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	$705,487	$454,055
Available-for-sale Securities, Gross Unrealized Gains	61	388
Available-for-sale Securities, Gross Unrealized Losses	-3,331	-477
Total Estimated Fair Value	702,217	453,966
Available-for-sale securities gross unrealized loss position
Estimated Fair Value	607,917	241,480
Available-for-sale Securities, Gross Unrealized Losses	-3,331	-474
Debt securities in government sponsored entities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	51,308	82,226
Available-for-sale Securities, Gross Unrealized Gains	10	18
Available-for-sale Securities, Gross Unrealized Losses	-55	-101
Total Estimated Fair Value	51,263	82,143
Available-for-sale securities gross unrealized loss position
Estimated Fair Value	36,084	73,362
Available-for-sale Securities, Gross Unrealized Losses	-55	-101
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	502,924	342,034
Available-for-sale Securities, Gross Unrealized Gains	46	312
Available-for-sale Securities, Gross Unrealized Losses	-2,882	-376
Total Estimated Fair Value	500,088	341,970
Available-for-sale securities gross unrealized loss position
Estimated Fair Value	428,078	168,118
Available-for-sale Securities, Gross Unrealized Losses	-2,882	-373
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	151,255	29,795
Available-for-sale Securities, Gross Unrealized Gains	5	58
Available-for-sale Securities, Gross Unrealized Losses	-394
Total Estimated Fair Value	150,866	29,853
Available-for-sale securities gross unrealized loss position
Estimated Fair Value	143,755
Available-for-sale Securities, Gross Unrealized Losses	($394)

Balance_Sheet_Account_Details_3

Balance Sheet Account Details (Details 2) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Balance Sheet Account Details [Abstract]
Due within one year	$238,198
After one but within five years	464,019
Total	$702,217	$453,966

Balance_Sheet_Account_Details_4

Balance Sheet Account Details (Details 3) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Accounts Receivable [Line Items]
Accounts receivable, gross	$294,917	$242,626
Allowance for doubtful accounts	-5,459	-3,680
Total accounts receivable, net	289,458	238,946
Accounts receivable from product and service sales [Member]
Accounts Receivable [Line Items]
Accounts receivable, gross	292,847	241,360
Other receivables [Member]
Accounts Receivable [Line Items]
Accounts receivable, gross	$2,070	$1,266

Balance_Sheet_Account_Details_5

Balance Sheet Account Details (Details 4) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Inventory [Abstract]
Raw materials	$70,316	$57,398
Work in process	94,102	70,016
Finished goods	26,726	26,685
Total inventory	$191,144	$154,099

Balance_Sheet_Account_Details_6

Balance Sheet Account Details (Details 5) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$480,001	$380,167
Accumulated depreciation	-214,737	-177,501
Total property and equipment, net	265,264	202,666
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	143,597	104,571
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	192,715	175,340
Computer hardware and software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	86,929	73,544
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	13,669	10,511
Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,670	7,670
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$35,421	$8,531

Balance_Sheet_Account_Details_7

Balance Sheet Account Details Balance Sheet Account Details (Details 6) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013
Goodwill Rollforward]
Balance at beginning of period	$723,061	$369,327
Current period acquisition	3,338	353,734
Purchase price allocation adjustments related to prior year acquisitions	-1,495
Balance at end of period	$724,904	$723,061

Balance_Sheet_Account_Details_8

Balance Sheet Account Details (Details 7) (USD $)	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012	Jan. 01, 2012
In Thousands, unless otherwise specified
Accrued Liabilities, Current [Abstract]
Accrued compensation expenses	$112,606	$82,705
Deferred revenue, current portion	75,294	50,834
Acquisition related contingent consideration liability, current portion	44,124	6,719
Accrued taxes payable	38,942	30,435
Customer deposits	20,274	13,569
Reserve for product warranties	15,616	10,407	10,136	11,966
Facility exit obligation, current portion	3,837	5,570
Other	24,583	18,881
Total accrued liabilities	$335,276	$219,120

Balance_Sheet_Account_Details_9

Balance Sheet Account Details (Details Textual) (USD $)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
	securities
Balance Sheet Account Details [Line Items]
Number of available-for-sale securities in a gross unrealized loss position	467
Cost-method investments in non-publicly traded companies	$37,200,000	$22,100,000
Cost method investment related (gain) loss	-4,427,000	-61,357,000	-45,911,000
Accrued expenditures included in capital expenditures	14,100,000
Capitalized computer software costs	16,500,000
Oxford Nanopore Technologies [Member]
Balance Sheet Account Details [Line Items]
Cost method investment related (gain) loss		-55,200,000
Other Cost Method Investment [Member]
Balance Sheet Account Details [Line Items]
Cost method investment related (gain) loss			$2,700,000

Acquisitions_Details

Acquisitions (Details) (USD $)	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill	$724,904	$723,061	$369,327
Verinata [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		9,151
Accounts receivable		2,801
Inventory		1,110
Prepaid expenses and other current assets		979
Property and equipment		12,083
Other assets		978
Intangible assets		176,490
Goodwill		227,453
Accounts payable		-2,539
Accrued liabilities		-3,803
Lease financing obligation		-9,695
Deferred tax liability		-18,741
Total purchase price		$396,267

Acquisitions_Details_1

Acquisitions (Details 1) (USD $)	12 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Feb. 21, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	$36,011
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful lives of intangible assets acquired in period (in years)	6 months
Fair Value	291
Verinata [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value		176,490
Verinata [Member] | Developed technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful lives of intangible assets acquired in period (in years)		13 years
Fair Value		170,200
Verinata [Member] | Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful lives of intangible assets acquired in period (in years)		5 years
Fair Value		4,690
Verinata [Member] | Trade name [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful lives of intangible assets acquired in period (in years)		2 years
Fair Value		$1,600

Acquisitions_Details_2

Acquisitions (Details 2) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 29, 2013	Dec. 30, 2012
Business Combinations [Abstract]
Net revenues	$1,433,935	$1,161,241
Net income	$113,869	$92,645
Net income per share-basic (in dollars per share)	$0.91	$0.75
Net income per share-diluted (in dollars per share)	$0.81	$0.69

Acquisitions_Details_3

Acquisitions (Details 3) (Contingent compensation expense [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Business Combination, Separately Recognized Transactions [Line Items]
Contingent compensation expense	$4,265	$13,610	$9,151
Research and development expense [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Contingent compensation expense	1,509	544	3,419
Selling, general and administrative expense [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Contingent compensation expense	$2,756	$13,066	$5,732

Acquisitions_Details_Textual

Acquisitions (Details Textual) (USD $)	12 Months Ended			0 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012	Feb. 21, 2013	Sep. 19, 2012	Dec. 26, 2014
Business Acquisition [Line Items]
Number of unvested stock options to purchase Illumina stock		512	251
Share price (in dollars per share)						$188.20
Expected dividend yield	0.00%
Goodwill	$724,904,000	$723,061,000	$369,327,000
Customer relationships [Member]
Business Acquisition [Line Items]
Weighted average useful life of identified intangible assets	6 months
Minimum [Member]
Business Acquisition [Line Items]
Useful life	3 years
Maximum [Member]
Business Acquisition [Line Items]
Useful life	7 years
Verinata [Member]
Business Acquisition [Line Items]
Business acquisition contract price				350,000,000
Contingent consideration payments, maximum				100,000,000
Business acquisition total consideration				396,300,000
Business acquisition net cash consideration				339,300,000
Fair value of contingent consideration to be settled in cash				56,200,000
Fair value of converted stock options				200,000
Amount deposited in escrow				30,000,000
Number of unvested stock options to purchase Illumina stock				400
Fair value of converted options				18,900,000
Share price (in dollars per share)				$48.36
Expected life				2 years 4 months
Weighted average risk free interest rate				0.32%
Weighted average annualized volatility				42.00%
Expected dividend yield				0.00%
Weighted average grant date fair value (in dollars per share)				$42.63
Expected volatility rate				50.00%
Risk free interest rate				0.26%
Consideration to identified intangible assets		176,490,000
Goodwill		227,453,000
Verinata [Member] | Developed technologies [Member]
Business Acquisition [Line Items]
Weighted average useful life of identified intangible assets				13 years
Verinata [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Weighted average useful life of identified intangible assets				5 years
Verinata [Member] | Trade name [Member]
Business Acquisition [Line Items]
Weighted average useful life of identified intangible assets				2 years
Verinata [Member] | Building [Member]
Business Acquisition [Line Items]
Discount rate for assessment of the acquisition date fair value				6.00%
Useful life				30 years
Future annual minimum payments due in 2015 and 2016	1,000,000
Future minimum payments due in 2017	8,400,000
Verinata [Member] | Minimum [Member]
Business Acquisition [Line Items]
Discount rate for assessment of the acquisition date fair value				6.00%
Verinata [Member] | Maximum [Member]
Business Acquisition [Line Items]
Discount rate for assessment of the acquisition date fair value				20.00%
Verinata [Member] | Preexisting relationship [Member]
Business Acquisition [Line Items]
Separately recognized transaction				-500,000
Verinata [Member] | Transaction costs [Member] | Acquisition related expense (gain), net [Member]
Business Acquisition [Line Items]
Separately recognized transaction		3,400,000
Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Goodwill		124,800,000
Series of individually immaterial business acquisitions [Member] | Developed technologies [Member]
Business Acquisition [Line Items]
Consideration to identified intangible assets		79,700,000
Weighted average useful life of identified intangible assets		8 years
BlueGnome [Member]
Business Acquisition [Line Items]
Contingent consideration payments, maximum					20,000,000
Business acquisition total consideration					95,500,000
Business acquisition net cash consideration					88,000,000
Fair value of contingent consideration to be settled in cash					7,500,000
Discount rate for assessment of the acquisition date fair value					30.00%
Goodwill					47,500,000
BlueGnome [Member] | Developed technologies [Member]
Business Acquisition [Line Items]
Consideration to identified intangible assets					25,000,000
Weighted average useful life of identified intangible assets					7 years
BlueGnome [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Consideration to identified intangible assets					16,800,000
Weighted average useful life of identified intangible assets					5 years
BlueGnome [Member] | Trade name [Member]
Business Acquisition [Line Items]
Consideration to identified intangible assets					7,100,000
Weighted average useful life of identified intangible assets					10 years
BlueGnome [Member] | Contingent compensation expense [Member] | Maximum [Member]
Business Acquisition [Line Items]
Separately recognized transaction					$20,000,000

Intangible_Assets_Details

Intangible Assets (Details) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Intangible asset, gross carrying amount	$451,359	$427,548
Accumulated amortization	-136,859	-96,375
Intangible assets, net	314,500	331,173
Licensed technologies [Member]
Intangible asset, gross carrying amount	83,956	48,361
Accumulated amortization	-39,423	-31,927
Intangible assets, net	44,533	16,434
Core technologies [Member]
Intangible asset, gross carrying amount	321,200	321,700
Accumulated amortization	-77,493	-45,534
Intangible assets, net	243,707	276,166
Customer relationships [Member]
Intangible asset, gross carrying amount	26,461	26,770
Accumulated amortization	-12,522	-7,376
Intangible assets, net	13,939	19,394
License agreements [Member]
Intangible asset, gross carrying amount	15,042	18,917
Accumulated amortization	-4,592	-4,947
Intangible assets, net	10,450	13,970
Trade name [Member]
Intangible asset, gross carrying amount	4,700	11,800
Accumulated amortization	-2,829	-6,591
Intangible assets, net	$1,871	$5,209

intangibles_Assets_Details_1

intangibles Assets (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired, gross amount	$36,011
Licensed technologies [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired, gross amount	35,595
Weighted average useful lives of intangible assets acquired in period (in years)	4 years 8 months
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired, gross amount	291
Weighted average useful lives of intangible assets acquired in period (in years)	6 months
License agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired, gross amount	$125
Weighted average useful lives of intangible assets acquired in period (in years)	7 years 2 months

Intangibles_Asses_Details_2

Intangibles Asses (Details 2) (USD $)	Dec. 28, 2014
In Thousands, unless otherwise specified
Intangibles Assets, Net (Excluding Goodwill) [Abstract]
2015	$52,994
2016	47,752
2017	43,276
2018	33,971
2019	30,685
Thereafter	105,822
Total	$314,500

Intangible_Assets_Details_Text

Intangible Assets (Details Textual)	12 Months Ended
	Dec. 28, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Finite-Lived Intangible Asset, Useful Life	8 years 1 month

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Change in estimated fair value of the contingent consideration liability
Change in estimated fair value, recorded in acquisition related (gain) expense, net	($5,356)	($18,784)	$1,975
Level 3 [Member]
Liability:
Acquisition related contingent consideration liabilities	44,124	49,480	12,519
Change in estimated fair value of the contingent consideration liability
Balance as of beginning of period	49,480	12,519	6,638
Additional liability recorded for acquisitions		60,184
Change in estimated fair value, recorded in acquisition related (gain) expense, net	-5,356	-18,784	1,975
Cash payments		-4,439	-3,594
Balance as of end of period	44,124	49,480	12,519
Level 3 [Member] | BlueGnome [Member]
Change in estimated fair value of the contingent consideration liability
Additional liability recorded for acquisitions			7,500
Fair Value, Measurements, Recurring [Member]
Assets:
Money market funds (cash equivalent)	431,172	478,755
Deferred compensation plan assets	23,486	17,805
Total assets measured at fair value	1,156,875	950,526
Liability:
Acquisition related contingent consideration liabilities	44,124	49,480
Deferred compensation liability	20,310	14,957
Total liabilities measured at fair value	64,434	64,437
Change in estimated fair value of the contingent consideration liability
Balance as of end of period	44,124	49,480
Fair Value, Measurements, Recurring [Member] | Debt securities in government sponsored entities [Member]
Assets:
Investments, fair value disclosure	51,263	82,143
Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Assets:
Investments, fair value disclosure	500,088	341,970
Fair Value, Measurements, Recurring [Member] | U.S. Treasury securities [Member]
Assets:
Investments, fair value disclosure	150,866	29,853
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Money market funds (cash equivalent)	431,172	478,755
Total assets measured at fair value	582,038	508,608
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. Treasury securities [Member]
Assets:
Investments, fair value disclosure	150,866	29,853
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Deferred compensation plan assets	23,486	17,805
Total assets measured at fair value	574,837	441,918
Liability:
Deferred compensation liability	20,310	14,957
Total liabilities measured at fair value	20,310	14,957
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Debt securities in government sponsored entities [Member]
Assets:
Investments, fair value disclosure	51,263	82,143
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate debt securities [Member]
Assets:
Investments, fair value disclosure	500,088	341,970
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Liability:
Acquisition related contingent consideration liabilities	44,124	49,480
Total liabilities measured at fair value	44,124	49,480
Change in estimated fair value of the contingent consideration liability
Balance as of end of period	$44,124	$49,480

Convertible_Senior_Notes_Detai

Convertible Senior Notes (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013
Summarized information about equity and liability components of convertible senior notes
Principal amount of convertible notes outstanding	$1,470,027	$949,570
Unamortized discount of liability component	-178,991	-80,977
Net carrying amount of liability component	1,291,036	868,593
Less: current portion	-304,256	-29,288
Long-term debt	986,780	839,305
Conversion option subject to cash settlement		282
Carrying value of equity component, net of debt issuance cost	215,283	274,304
Fair value of outstanding notes	$2,021,750	$1,428,743
Weighted average remaining amortization period of discount on the liability component	5 years 2 months	2 years 2 months

Convertible_Senior_Notes_Detai1

Convertible Senior Notes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014
Extinguishment of Debt [Line Items]
Cash paid for principal of notes converted	$1,244,721
2014 Notes [Member]
Extinguishment of Debt [Line Items]
Cash paid for principal of notes converted	29,570
Conversion value over principal amount paid in shares of common stock	$196,095
Number of shares of common stock issued upon conversion	1,151

Convertible_Senior_Notes_Detai2

Convertible Senior Notes (Details Textual) (USD $)	12 Months Ended		0 Months Ended	12 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Jun. 11, 2014	Jan. 01, 2012	Dec. 30, 2007
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs	$1,132,378,000
Debt, Long-term and Short-term, Combined Amount	1,291,036,000	868,593,000
Carrying value of equity component, net of debt issuance cost	215,283,000	274,304,000
Cash paid for principal of notes converted	1,244,721,000
Loss on extinguishment of debt	-31,360,000	-555,000
Exercise price of warrants held by hedging counter parties (in dollars per share)					$31.43
2019 and 2021 Notes [Member]
Debt Instrument [Line Items]
Issuance of convertible senior notes			1,150,000,000
Debt issuance price as a percentage of principal			100.00%
Proceeds from Debt, Net of Issuance Costs			1,132,400,000
Conversion rate per 1,000 principal amount of notes			3.9318
Principal amount used in calculating incremental share settlement amount			1,000
Conversion Price			$254.34
Circumstances of converting notes at referred conversion ratio			(1) during the five business-day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price per 2019 and 2021 Note for each day of such measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such day; (2) during any calendar quarter (and only during that quarter) after the calendar quarter ending September 30, 2014, if the last reported sale price of the Company’s common stock for 20 or more trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter exceeds 130% of the applicable conversion price in effect on the last trading day of the immediately preceding calendar quarter; (3) upon the occurrence of specified events described in the indenture for the 2019 and 2021 Notes; and (4) at any time on or after March 15, 2019 for the 2019 Notes, or March 15, 2021 for the 2021 Notes, through the second scheduled trading day immediately preceding the maturity date
Number of consecutive trading days in the measurement period			10 days
Conversion triggering common stock trading price as a percentage of price last reported in Measurement period converted at conversion rate			less than 98%
Number of business days notes are convertible after measurement period			20 days
Number of consecutive trading days on which trading price is examined for triggering of conversion			30 days
Conversion triggering common stock price as a percentage of applicable conversion price in effect on the last trading day of the immediately preceding calendar quarter			exceeds 130%
Observation period for the observation value			20 days
Repurchase Price as a Percentage of Principal Amount upon designated events			100.00%
Debt, Long-term and Short-term, Combined Amount			971,500,000
Carrying value of equity component, net of debt issuance cost			161,200,000
Proceeds from Issuance of Debt			1,132,700,000
2019 Notes [Member]
Debt Instrument [Line Items]
Issuance of convertible senior notes	632,500,000
Interest rate on convertible senior notes			0.00%
Debt Instrument, Maturity Date			15-Jun-19
Effective interest rate used to measure fair value of convertible senior note			2.90%
2021 Notes [Member]
Debt Instrument [Line Items]
Issuance of convertible senior notes	517,500,000
Interest rate on convertible senior notes			0.50%
Debt Instrument, Maturity Date			15-Jun-21
Effective interest rate used to measure fair value of convertible senior note			3.50%
2016 Notes [Member]
Debt Instrument [Line Items]
Issuance of convertible senior notes	320,000,000			920,000,000
Interest rate on convertible senior notes				0.25%
Debt Instrument, Maturity Date				15-Mar-16
Debt issuance price as a percentage of principal				98.25%
Conversion rate per 1,000 principal amount of notes				11.9687
Principal amount used in calculating incremental share settlement amount				1,000
Conversion Price				$83.55
Circumstances of converting notes at referred conversion ratio				(1) during the five business-day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price per 2016 Note for each day of such measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such day; (2) during any calendar quarter (and only during that quarter) after the calendar quarter ending March 31, 2011, if the last reported sale price of the Company’s common stock for 20 or more trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter exceeds 130% of the applicable conversion price in effect on the last trading day of the immediately preceding calendar quarter; (3) upon the occurrence of specified events described in the indenture for the 2016 Notes; and (4) at any time on or after December 15, 2015 through the second scheduled trading day immediately preceding the maturity date.
Number of consecutive trading days in the measurement period				10 days
Conversion triggering common stock trading price as a percentage of price last reported in Measurement period converted at conversion rate				less than 98%
Number of business days notes are convertible after measurement period				20 days
Number of consecutive trading days on which trading price is examined for triggering of conversion				30 days
Conversion triggering common stock price as a percentage of applicable conversion price in effect on the last trading day of the immediately preceding calendar quarter				exceeds 130%
Observation period for the observation value				20 days
Repurchase Price as a Percentage of Principal Amount upon designated events				100.00%
Effective interest rate used to measure fair value of convertible senior note				4.50%
Debt, Long-term and Short-term, Combined Amount				748,500,000
Carrying value of equity component, net of debt issuance cost				155,400,000
Proceeds from Issuance of Debt				903,900,000
Debt Issuance Costs				400,000
Amortization period for debt issuance costs				5 years
Convertible senior note conversion start period	1-Apr-14
Convertible senior note conversion end period	31-Mar-15
Debt Instrument, Repurchased Face Amount			600,000,000
Cash paid for principal of notes converted	1,244,700,000
Effective interest rate used to measure fair value of converted notes upon conversion			1.20%
Debt Instrument, Repurchase Amount, Debt Component			588,800,000
Debt Instrument, Repurchase Amount, Equity Component			655,900,000
Loss on extinguishment of debt			31,400,000
If-converted value in excess of principal	393,300,000
2014 Notes [Member]
Debt Instrument [Line Items]
Issuance of convertible senior notes					400,000,000
Interest rate on convertible senior notes					0.63%
Debt Instrument, Maturity Date					15-Feb-14
Effective interest rate used to measure fair value of convertible senior note					8.30%
Convertible senior note conversion start period	1-Apr-12
Convertible senior note conversion end period	12-Feb-14
Cash paid for principal of notes converted	$29,570,000
Maximum Shares Entitles to Purchase Shares Under Hedge Transaction Upon Issuance of Convertible Senior Notes					18.3
Strike price under hedge transaction upon issuance of the convertible senior notes					$21.83
2014 Notes [Member] | Warrant [Member]
Debt Instrument [Line Items]
Class of Warrant or Right, Outstanding					18.3
Exercise price of warrants held by hedging counter parties (in dollars per share)					$31.43

Commitments_Details

Commitments (Details) (USD $)	Dec. 28, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Operating lease, current - 2015	$35,210
Operating lease, due in two years - 2016	38,892
Operating lease, due in three years - 2017	37,064
Operating lease, due in four years - 2018	37,747
Operating lease, due in five years - 2019	39,656
Operating lease, due after five years - Thereafter	415,052
Operating lease, total future minimum payments due	603,621
Sublease, current - 2015	-2,900
Sublease, receivable in two years - 2016	-2,924
Sublease, receivable in three years - 2017	-2,708
Sublease, receivable in four years - 2018	-2,789
Sublease, receivable in five years - 2019	-2,873
Sublease, receivable after five years - Thereafter	-11,837
Sublease, total future minimum receivable	-26,031
Operating leases, net - current - 2015	32,310
Operating lease, net, due in two years - 2016	35,968
Operating lease, net, due in three years - 2017	34,356
Operating lease, net, due in four years - 2018	34,958
Operating lease, net, due in five years - 2019	36,783
Operating lease, net, due after five years - Thereafter	403,215
Operating lease, total net future minimum payments due	$577,590

Commitments_Details_1

Commitments (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Commitments and Contingencies Disclosure [Abstract]
Headquarters facility exit obligation balance, beginning of period	$38,218	$45,352	$25,049
Adjustment to facility exit obligation	2,555	-114	24,878
Accretion of interest expense	2,638	2,738	2,129
Cash payments	-5,711	-9,758	-6,704
Headquarters facility exit obligation balance, end of period	$37,700	$38,218	$45,352

Commitments_Details_2

Commitments (Details 2) (USD $)	Dec. 28, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Royalties, Future Minimum Payments, Due in 2015	$8,650
Royalties, Future Minimum Payments, Due in 2016	12,470
Royalties, Future Minimum Payments, Due in 2017	13,500
Royalties, Future Minimum Payments, Due in 2018	18,475
Royalties, Future Minimum Payments, Due in 2019	23,480
Royalties, Future Minimum Payments, Due Thereafter	23,550
Total minimum royalty payments	$100,125

Commitments_Details_3

Commitments (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Reserve for product warranties
Balance as of beginning of period	$10,407	$10,136	$11,966
Additions charged to cost of revenue	24,150	15,674	17,279
Repairs and replacements	-18,941	-15,403	-19,109
Balance as of end of period	$15,616	$10,407	$10,136

Commitments_Details_Textual

Commitments (Details Textual) (USD $)	12 Months Ended			0 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012	Dec. 31, 2014	Dec. 30, 2014
					sqft
Subsequent Event [Line Items]
Operating Leases, Future Minimum Payments Due	$603,621,000
Sublease initial term	10 years
Line of Credit Issuance Amount	8,000,000
Letters of credit amount at end of lease term	0
Line of Credit Outstanding Balance	7,200,000
Rent expense	33,200,000	28,100,000	21,400,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Lease square footage					360,000
Initial Term				16 years
Lease Commencement Date				1-Jul-17
Number of lease renewal options					3
Lease renewal option term				5 years
Operating Leases, Future Minimum Payments Due					$204,000,000

Sharebased_Compensation_Expens2

Share-based Compensation Expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Share-based Compensation
Share-based compensation expense before taxes	$152,551	$105,826	$94,324
Related income tax benefits	-44,194	-32,819	-30,759
Share-based compensation expense, net of taxes	108,357	73,007	63,565
Cost of product revenue [Member]
Share-based Compensation
Share-based compensation expense before taxes	9,451	6,223	7,575
Cost of service and other revenue [Member]
Share-based Compensation
Share-based compensation expense before taxes	1,204	777	461
Research and development expense [Member]
Share-based Compensation
Share-based compensation expense before taxes	50,880	37,439	30,879
Selling, general and administrative [Member]
Share-based Compensation
Share-based compensation expense before taxes	$91,016	$61,387	$55,409

Sharebased_Compensation_Expens3

Share-based Compensation Expense (Details 1) (USD $)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Expected dividend yield	0.00%
Stock Options [Member]
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Risk-free interest rate, minimum		0.14%	0.56%
Risk-free interest rate, maximum		1.86%	0.93%
Expected volatility, minimum		30.00%	41.00%
Expected volatility, maximum		44.00%	48.00%
Expected dividend yield		0.00%	0.00%
Weighted-average grant-date fair value per share, options		40.66	15.47
Stock Options [Member] | Maximum [Member]
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Expected term		9 years 5 months	6 years 7 months
Stock Options [Member] | Minimum [Member]
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Expected term		0 years 9 months	4 years
Employee Stock Purchase Rights [Member]
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Risk-free interest rate, minimum	0.05%	0.08%	0.09%
Risk-free interest rate, maximum	0.13%	0.15%	0.17%
Expected volatility, minimum	38.00%	31.00%	33.00%
Expected volatility, maximum	41.00%	32.00%	64.00%
Expected dividend yield	0.00%	0.00%	0.00%
Weighted-average grant-date fair value per share, ESPP	44.64	19.3	16.45
Employee Stock Purchase Rights [Member] | Maximum [Member]
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Expected term	1 year	1 year	1 year
Employee Stock Purchase Rights [Member] | Minimum [Member]
Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted
Expected term	6 months	6 months	6 months

Sharebased_Compensation_Expens4

Share-based Compensation Expense (Details Textual) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 28, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unrecognized compensation cost related to stock options, restricted stock units and ESPP shares issued to date	$280.60
Weighted-average period of unrecognized compensation cost related to stock options, restricted stock, and ESPP shares issued to date	2 years 1 month

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Equity [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	2,900,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$35.94
Options
Options, Outstanding at Period Start	5,724,000	8,351,000	10,378,000
Options, Granted		512,000	251,000
Options, Exercised	-2,478,000	-3,006,000	-2,071,000
Options, Cancelled	-35,000	-133,000	-207,000
Options, Outstanding at Period End	3,211,000	5,724,000	8,351,000
Weighted-Average Exercise Price
Weighted-Average Exercise Price, Outstanding at Period Start (in dollars per share)	$32.64	$32.10	$29.69
Weighted Average Exercise Price, Granted (in dollars per share)		$14.74	$40.79
Weighted Average Exercise Price, Exercised (in dollars per share)	$29.93	$27.70	$20.34
Weighted Average Exercise Price, Cancelled (in dollars per share)	$31.73	$41.80	$39.18
Weighted-Average Exercise Price, Outstanding at Period End (in dollars per share)	$34.74	$32.64	$32.10

Stockholders_Equity_Details_1

Stockholders' Equity (Details 1) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Restricted Stock Awards [Member]
Restricted stock
Restricted Stock, Outstanding at Period Start	248	465	230
Restricted Stock, Awarded			312
Restricted Stock, Vested	-140	-217	-77
Restricted Stock, Outstanding at Period End	108	248	465
Weighted Average Grant-Date Fair Value per Share
Weighted Average Grant Date Fair Value per Share, Outstanding at Period Start (in dollars per share)	$53.46	$53.84	$65.95
Weighted Average Grant Date Fair Value per Share, Awarded (in dollars per share)			$47.91
Weighted Average Grant Date Fair Value per Share, Vested (in dollars per share)	$47.90	$54.27	$65.95
Weighted Average Grant Date Fair Value per Share, Outstanding at Period End (in dollars per share)	$56.62	$53.46	$53.84
Restricted Stock Units [Member]
Restricted stock
Restricted Stock, Outstanding at Period Start	3,628	3,660	3,476
Restricted Stock, Awarded	780	1,532	1,640
Restricted Stock, Vested	-1,383	-1,308	-1,062
Restricted Stock, Cancelled	-184	-256	-394
Restricted Stock, Outstanding at Period End	2,841	3,628	3,660
Weighted Average Grant-Date Fair Value per Share
Weighted Average Grant Date Fair Value per Share, Outstanding at Period Start (in dollars per share)	$59.66	$45.49	$41.87
Weighted Average Grant Date Fair Value per Share, Awarded (in dollars per share)	$172.53	$77.53	$48.52
Weighted Average Grant Date Fair Value per Share, Vested (in dollars per share)	$55.44	$42.97	$38.48
Weighted Average Grant Date Fair Value per Share, Cancelled (in dollars per share)	$65.09	$49.24	$45.05
Weighted Average Grant Date Fair Value per Share, Outstanding at Period End (in dollars per share)	$92.35	$59.66	$45.49
Performance Stock Units [Member]
Restricted stock
Restricted Stock, Outstanding at Period Start	1,101	587
Restricted Stock, Awarded	968	584	599
Restricted Stock, Vested	-753
Restricted Stock, Cancelled	-59	-70	-12
Restricted Stock, Outstanding at Period End	1,257	1,101	587
Weighted Average Grant-Date Fair Value per Share
Weighted Average Grant Date Fair Value per Share, Outstanding at Period Start (in dollars per share)	$54.64	$49.64
Weighted Average Grant Date Fair Value per Share, Awarded (in dollars per share)	$104.52	$59.16	$49.66
Weighted Average Grant Date Fair Value per Share, Vested (in dollars per share)	$49.52
Weighted Average Grant Date Fair Value per Share, Cancelled (in dollars per share)	$52.87	$50.42	$50.54
Weighted Average Grant Date Fair Value per Share, Outstanding at Period End (in dollars per share)	$96.21	$54.64	$49.64

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax intrinsic value of outstanding restricted and performance stock	$20,321	$27,384	$25,437
Fair value of restricted and performance stock vested	6,712	11,750	5,039
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax intrinsic value of outstanding restricted and performance stock	534,708	400,421	200,383
Fair value of restricted and performance stock vested	76,646	56,212	40,870
Performance Shares Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax intrinsic value of outstanding restricted and performance stock	236,606	121,555	32,149
Fair value of restricted and performance stock vested	$37,313

Stockholders_Equity_Details_Te

Stockholders' Equity (Details Textual) (USD $)	1 Months Ended	12 Months Ended
	Jul. 28, 2013	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012	Dec. 26, 2014	Dec. 30, 2007	Apr. 29, 2012	Jan. 30, 2014	Jan. 25, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercisable (in shares)		2,900,000
Stock options exercisable outstanding weighted average exercise price per share (in dollars per share)		$35.94
Weighted average remaining life in years of options outstanding		4 years 3 months 20 days
Weighted average remaining life in years of options exercisable		4 years 1 month 17 days
Aggregate intrinsic value of options outstanding		$492,800,000
Aggregate intrinsic value of options exercisable		444,200,000
Share price (in dollars per share)					$188.20
Total intrinsic value of options exercised		330,500,000	141,700,000	60,600,000
Total fair value of options vested		17,200,000	24,000,000	31,900,000
Exercise price of warrants held by hedging counter parties (in dollars per share)						$31.43
Number of common shares callable by warrants settled in period	3,000,000
Number of common shares called by warrants						18,300,000
Payments on retirement of warrants	125,000,000		-125,000,000
Repurchase of common shares (in shares)				1,900,000
Common stock repurchases (in dollars)		237,183,000	50,020,000	82,522,000
Dollar amount remaining in authorized stock repurchase program		130,400,000
Preferred stock, par value (in dollars per share)		$0.01	$0.01
Price per right Board of Directors are entitled to redeem rights (in dollars per Right)						$31.43
April 18, 2012 Discretionary Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common shares (in shares)		1,500,000	900,000
Stock repurchase program authorized amount							250,000,000
January 30, 2014 Stock Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program authorized amount								$250,000,000
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Percentage of options vesting on the first anniversary of the grant date		20.00%
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		5 years
Percentage of options vesting on the first anniversary of the grant date		25.00%
Maximum term of each grant of options		10 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Vesting percentage, 1st anniversary		15.00%
Vesting percentage, 2nd anniversary		20.00%
Vesting percentage, 3rd anniversary		30.00%
Vesting percentage, 4th anniversary		35.00%
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock award performance period		3 years
Performance Stock Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares approved issuable at end of performance period		150.00%
2005 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in the maximum number of shares of common stock authorized for issuance (in shares)			5,000,000
2005 Illumina, 2005 Solexa, and 2008 Verinata Stock Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance		5,300,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance		14,700,000	15,000,000
ESPP Number of shares authorized		15,500,000
Specified percentage of the fair market value of the common stock on the first or last day of the offering period whichever is lower at which stock is purchased		85.00%
Annual percent increases of shares available for issuance		3.00%
ESPP Annual increases of shares available for issuance		3,000,000
Total shares issued under the ESPP		300,000	400,000	300,000
Stockholder Rights Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of warrants held by hedging counter parties (in dollars per share)									$0.00
Preferred stock, par value (in dollars per share)									$0.01
Dividend price per share of Series A Junior Participating Preferred Stock (in dollars per Right)									275
Dividend portion of a share of Series A Junior Participating Preferred Stock									0.001
Minimum percent ownership of outstanding common stock required to exercise rights									15.00%
Price per right Board of Directors are entitled to redeem rights (in dollars per Right)									$0.00
Number of shares per Right									1
Stockholder Rights Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent ownership of outstanding common stock required prior to exchange by board of directors									15.00%
Stockholder Rights Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent ownership of outstanding common stock required prior to exchange by board of directors									50.00%

Legal_Proceedings_Legal_Procee

Legal Proceedings Legal Proceedings (Details Textual) (USD $)	0 Months Ended	12 Months Ended
	Jul. 02, 2013	Dec. 28, 2014	Dec. 29, 2013	Sep. 28, 2014
Loss Contingencies [Line Items]
Final Amended Judgment amount	$115,100,000
Final Amended Judgment royalty rate	8.00%
Legal contingencies		-74,338,000	115,369,000
Syntrix [Member]
Loss Contingencies [Line Items]
Legal contingencies		-109,400,000	132,900,000
Settlement payment		70,000,000
Loss Contingency Accrual				148,800,000
Remaining amortization of settlement payment allocated to intangible assets		4 years 9 months 20 days
Release of ongoing royalty amount deposited with the Court		33,500,000
Sequenom [Member]
Loss Contingencies [Line Items]
Upfront payment for Sequenom contract		50,000,000
Cost of Sales [Member] | Syntrix [Member]
Loss Contingencies [Line Items]
Legal contingencies		-27,300,000
Operating Expense [Member] | Syntrix [Member]
Loss Contingencies [Line Items]
Legal contingencies		-82,100,000	114,600,000
Operating Expense [Member] | Sequenom [Member]
Loss Contingencies [Line Items]
Legal contingencies		1,200,000
Research and development expense [Member] | Sequenom [Member]
Loss Contingencies [Line Items]
Upfront payment for Sequenom contract		48,800,000
Finite-Lived Intangible Assets [Member] | Syntrix [Member]
Loss Contingencies [Line Items]
Settlement payment		29,500,000
Release of past damages [Member] | Syntrix [Member]
Loss Contingencies [Line Items]
Settlement payment		$40,500,000

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Income Tax Disclosure [Abstract]
United States	$176,974	($53,703)	$102,296
Foreign	271,784	213,017	120,312
Income before income taxes	$448,758	$159,314	$222,608

Income_Taxes_Details_1

Income Taxes (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Current:
Federal	$60,984	$78,419	$57,285
State	12,381	8,854	10,121
Foreign	41,815	39,416	31,504
Total current provision	115,180	126,689	98,910
Deferred:
Federal	-3,191	-69,102	-7,724
State	-4,974	-15,222	-7,708
Foreign	-11,608	-8,359	-12,124
Total deferred benefit	-19,773	-92,683	-27,556
Total tax provision	$95,407	$34,006	$71,354

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	$157,065	$55,760	$77,913
State, net of federal benefit	5,023	647	4,056
Research and other credits	-16,144	-10,977	-2,613
Change in valuation allowance	-4,212	10,544	-37
Change in fair value of contingent consideration	-1,321	-3,859
Impact of foreign operations	-42,215	-18,006	-11,470
Other	-2,789	-103	3,505
Total tax provision	$95,407	$34,006	$71,354

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Net operating losses	$47,738	$66,969
Tax credits	32,192	36,277
Other accruals and reserves	41,676	86,716
Stock compensation	54,570	36,728
Deferred rent	25,975	16,823
Inventory adjustments	12,003	9,034
Other amortization	28,203	9,571
Other	24,045	18,244
Total gross deferred tax assets	266,402	280,362
Valuation allowance on deferred tax assets	-15,191	-19,132
Total deferred tax assets	251,211	261,230
Deferred tax liabilities:
Purchased intangible amortization	-85,612	-98,671
Convertible debt	-61,383	-27,821
Property and equipment	-16,521	-13,311
Other	-1,670	-6,349
Total deferred tax liabilities	-165,186	-146,152
Net deferred tax assets	$86,025	$115,078

Income_Taxes_Details_4

Income Taxes (Details 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$49,046	$37,585	$28,396
Increases related to prior year tax positions	426	4,794	2,573
Decreases related to prior year tax positions	-804	-223	-69
Increases related to current year tax positions	8,756	7,503	6,685
Decreases related to lapse of statute of limitations	-5,336	-613
Balance at end of year	$52,088	$49,046	$37,585

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Income Taxes [Line Items]
U.S. federal statutory tax rate	35.00%
Valuation allowance	$15,191,000	$19,132,000
Change in valuation allowance	-3,900,000
Excess tax benefits realized	126,477,000	53,032,000	17,015,000
Unrealized excess tax benefits associated with share-based compensation	36,800,000
Decrease to the provision for income taxes	15,600,000
Increase to net income per diluted share	$0.10
Undistributed earnings of foreign subsidiaries	395,600,000
Uncertain tax positions that would reduce annual effective tax rate, if recognized	42,600,000	40,100,000
Potential interest penalties on uncertain tax positions	700,000	1,000,000	800,000
Liability recorded for potential interest and penalties	4,400,000	3,500,000
Federal [Domain]
Income Taxes [Line Items]
Net operating loss carryforwards	163,600,000
Federal and state tax credit carryforwards	15,300,000
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	295,000,000
Federal and state tax credit carryforwards	63,700,000
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Change in valuation allowance	-10,400,000
Research Tax Credit Carryforward [Member]
Income Taxes [Line Items]
Change in valuation allowance	$6,000,000
Singapore [Member]
Income Taxes [Line Items]
Foreign statutory tax rates	17.00%
United Kingdom [Member]
Income Taxes [Line Items]
Foreign statutory tax rates	21.50%

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details Textual) (USD $)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Matching contributions	$9,500,000	$7,000,000	$5,500,000
Percent of base salary available for contribution to the deferred compensation plan	80.00%
Percent of all other forms of compensation available for contribution to the deferred compensation plan	100.00%
Fair Value, Measurements, Recurring [Member]
Assets of the Deferred Compensation Plan rabbi trust	23,486,000	17,805,000
Liabilities of the Deferred Compensation Plan rabbi trust	20,310,000	14,957,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets of the Deferred Compensation Plan rabbi trust	23,486,000	17,805,000
Liabilities of the Deferred Compensation Plan rabbi trust	$20,310,000	$14,957,000

Segment_Information_Geographic2

Segment Information, Geographic Data, and Significant Customers (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$512,379	$480,630	$447,568	$420,781	$387,326	$356,800	$346,094	$330,958	$1,861,358	$1,421,178	$1,148,516
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									950,703	714,662	568,443
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									466,536	354,682	291,404
Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									342,702	276,442	232,498
Other markets [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$101,417	$75,392	$56,171

Segment_Information_Geographic3

Segment Information, Geographic Data, and Significant Customers (Details 1) (USD $)	Dec. 28, 2014	Dec. 29, 2013
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$265,264	$202,666
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	204,717	150,470
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	31,965	24,122
Singapore [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	22,326	21,311
Other countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$6,256	$6,763

Segment_Information_Geographic4

Segment Information, Geographic Data, and Significant Customers (Details Textual)	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Products and Services, Consumables [Member]
Revenue from External Customer [Line Items]
Percent of sales	56.00%	62.00%	64.00%
Products and Services, Instruments [Member]
Revenue from External Customer [Line Items]
Percent of sales	30.00%	26.00%	27.00%

Quarterly_Financial_Informatio2

Quarterly Financial Information (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Quarterly Financial Information Disclosure [Abstract]
Fiscal year quarterly operating cycle	P13W	P13W	P13W	P13W	P13W	P13W	P13W	P13W
Total revenue	$512,379	$480,630	$447,568	$420,781	$387,326	$356,800	$346,094	$330,958	$1,861,358	$1,421,178	$1,148,516
Gross profit	384,937	333,941	300,540	278,292	259,246	209,940	223,409	219,292	1,297,710	911,887	773,528
Net income (loss)	$153,280	$93,489	$46,605	$59,977	$80,661	$31,357	$35,877	($22,587)	$353,351	$125,308	$151,254
Net income (loss) per share, basic	$1.08	$0.66	$0.36	$0.47	$0.64	$0.25	$0.29	($0.18)	$2.61	$1	$1.23
Net income (loss) per share, diluted	$1.03	$0.63	$0.31	$0.40	$0.56	$0.22	$0.26	($0.18)	$2.37	$0.90	$1.13

SCHEDULE_II_VALUATION_AND_QUAL1

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) (Allowance for doubtful accounts [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 28, 2014		Dec. 29, 2013		Dec. 30, 2012
Allowance for doubtful accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$3,680		$4,280		$3,997
Additions Charged to Expenses/(Reductions from) Revenue(1)	1,870	[1]	-422	[1]	2,191	[1]
Deductions	-91	[2]	-178	[2]	-1,908	[2]
Balance at End of Period	$5,459		$3,680		$4,280
[1]	Additions to and reductions from allowance for doubtful accounts are recorded to selling, general and administrative expense.
[2]	Deductions for allowance for doubtful accounts are for accounts receivable written off.