Exelixis (EXEL) 10-Q 5 Aug 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jul. 02, 2021	Jul. 26, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jul. 2, 2021
Document Transition Report	false
Entity File Number	000-30235
Entity Registrant Name	EXELIXIS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3257395
Entity Address, Address Line One	1851 Harbor Bay Parkway
Entity Address, City or Town	Alameda,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94502
City Area Code	650
Local Phone Number	837-7000
Title of 12(b) Security	Common Stock $.001 Par Value per Share
Trading Symbol	EXEL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		315,048,788
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000939767
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021
Current assets:
Cash and cash equivalents	$ 492,462	$ 319,217
Short-term investments	854,171	887,319
Trade receivables, net	171,753	160,875
Inventory	24,982	20,973
Prepaid expenses and other current assets	49,878	57,011
Total current assets	1,593,246	1,445,395
Long-term investments	345,613	330,751
Property and equipment, net	95,133	67,384
Deferred tax assets, net	134,667	156,711
Goodwill	63,684	63,684
Other long-term assets	134,928	73,408
Total assets	2,367,271	2,137,333
Current liabilities:
Accounts payable	20,450	23,632
Accrued compensation and benefits	48,324	51,189
Accrued clinical trial liabilities	67,075	52,251
Rebates and fees due to customers	31,197	20,683
Accrued collaboration liabilities	24,428	12,456
Other current liabilities	63,852	44,447
Total current liabilities	255,326	204,658
Long-term portion of deferred revenues	8,577	3,755
Long-term portion of operating lease liabilities	53,223	49,086
Other long-term liabilities	7,068	721
Total liabilities	324,194	258,220
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000 shares authorized and no shares issued	0	0
Common stock, $0.001 par value; 400,000 shares authorized; issued and outstanding: 314,822 and 311,627 at June 30, 2021 and December 31, 2020, respectively	315	312
Additional paid-in capital	2,390,654	2,321,895
Accumulated other comprehensive income	1,985	4,476
Accumulated deficit	(349,877)	(447,570)
Total stockholders’ equity	2,043,077	1,879,113
Total liabilities and stockholders’ equity	$ 2,367,271	$ 2,137,333

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jul. 02, 2021	Jan. 01, 2021
Preferred stock
Par value (in dollars per share)	$ 0.001	$ 0.001
Shares authorized (in shares)	10,000,000	10,000,000
Shares issued (in shares)	0	0
Common stock
Par value (in dollars per share)	$ 0.001	$ 0.001
Shares authorized (in shares)	400,000,000	400,000,000
Shares issued (in shares)	314,822,000	311,627,000
Shares outstanding (in shares)	314,822,000	311,627,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Revenues:
Total revenues	$ 385,177	$ 259,479	$ 655,407	$ 486,394
Operating expenses:
Cost of goods sold	14,884	9,221	28,082	18,510
Research and development	148,790	114,933	308,078	216,810
Selling, general and administrative	98,495	59,791	200,846	122,731
Total operating expenses	262,169	183,945	537,006	358,051
Income from operations	123,008	75,534	118,401	128,343
Interest income	1,891	5,162	4,573	12,382
Other income (expense), net	(11)	0	(101)	6
Income before income taxes	124,888	80,696	122,873	140,731
Provision for income taxes	28,796	13,875	25,180	25,298
Net income	$ 96,092	$ 66,821	$ 97,693	$ 115,433
Net income per share:
Basic (in dollars per share)	$ 0.31	$ 0.22	$ 0.31	$ 0.38
Diluted (in dollars per share)	$ 0.30	$ 0.21	$ 0.30	$ 0.36
Weighted-average common shares outstanding:
Basic (in shares)	314,117	307,807	313,295	306,598
Diluted (in shares)	322,941	318,144	322,114	316,992
Net product revenues
Revenues:
Total revenues	$ 284,248	$ 178,730	$ 511,460	$ 372,610
License revenues
Revenues:
Total revenues	39,640	59,234	67,168	80,113
Collaboration services revenues
Revenues:
Total revenues	$ 61,289	$ 21,515	$ 76,779	$ 33,671

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 96,092	$ 66,821	$ 97,693	$ 115,433
Other comprehensive income (loss):
Net unrealized gains (losses) on available-for-sale debt securities, net of tax impact of ($257), $2,287, ($756) and $1,346, respectively	(755)	8,062	(2,491)	4,771
Comprehensive income	$ 95,337	$ 74,883	$ 95,202	$ 120,204

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on available-for-sale debt securities, net of tax impact	$ (257)	$ 2,287	$ (756)	$ 1,346

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Jan. 03, 2020		304,831
Beginning balance at Jan. 03, 2020	$ 1,685,970	$ 305	$ 2,241,947	$ 3,069	$ (559,351)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	115,433				115,433
Other comprehensive income (loss)	4,771			4,771
Issuance of common stock under equity incentive and stock purchase plans (in shares)		4,055
Issuance of common stock under equity incentive and stock purchase plans	17,955	$ 4	17,951
Stock transactions associated with taxes withheld on equity awards	(20,941)		(20,941)
Stock-based compensation	30,136		30,136
Ending balance (in shares) at Jul. 03, 2020		308,886
Ending balance at Jul. 03, 2020	1,833,324	$ 309	2,269,093	7,840	(443,918)
Beginning balance (in shares) at Apr. 03, 2020		305,780
Beginning balance at Apr. 03, 2020	1,747,652	$ 306	2,258,307	(222)	(510,739)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	66,821				66,821
Other comprehensive income (loss)	8,062			8,062
Issuance of common stock under equity incentive and stock purchase plans (in shares)		3,106
Issuance of common stock under equity incentive and stock purchase plans	13,783	$ 3	13,780
Stock transactions associated with taxes withheld on equity awards	(19,148)		(19,148)
Stock-based compensation	16,154		16,154
Ending balance (in shares) at Jul. 03, 2020		308,886
Ending balance at Jul. 03, 2020	$ 1,833,324	$ 309	2,269,093	7,840	(443,918)
Beginning balance (in shares) at Jan. 01, 2021	311,627	311,627
Beginning balance at Jan. 01, 2021	$ 1,879,113	$ 312	2,321,895	4,476	(447,570)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	97,693
Other comprehensive income (loss)	(2,491)			(2,491)
Issuance of common stock under equity incentive and stock purchase plans (in shares)		3,195
Issuance of common stock under equity incentive and stock purchase plans	15,487	$ 3	15,484
Stock transactions associated with taxes withheld on equity awards	(9,413)		(9,413)
Stock-based compensation	$ 62,688		62,688
Ending balance (in shares) at Jul. 02, 2021	314,822	314,822
Ending balance at Jul. 02, 2021	$ 2,043,077	$ 315	2,390,654	1,985	(349,877)
Beginning balance (in shares) at Apr. 02, 2021		313,262
Beginning balance at Apr. 02, 2021	1,911,187	$ 313	2,354,103	2,740	(445,969)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	96,092				96,092
Other comprehensive income (loss)	(755)			(755)
Issuance of common stock under equity incentive and stock purchase plans (in shares)		1,560
Issuance of common stock under equity incentive and stock purchase plans	11,285	$ 2	11,283
Stock transactions associated with taxes withheld on equity awards	(2,767)		(2,767)
Stock-based compensation	$ 28,035		28,035
Ending balance (in shares) at Jul. 02, 2021	314,822	314,822
Ending balance at Jul. 02, 2021	$ 2,043,077	$ 315	$ 2,390,654	$ 1,985	$ (349,877)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020
Statement of Cash Flows [Abstract]
Net income	$ 97,693	$ 115,433
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	6,895	4,376
Stock-based compensation	62,688	30,136
Non-cash lease expense	2,586	2,383
Deferred taxes	22,800	22,793
Other, net	22,831	726
Changes in operating assets and liabilities:
Trade receivables, net	(12,313)	(2,014)
Inventory	(8,020)	(7,049)
Prepaid expenses and other assets	(12,296)	(18,954)
Deferred revenue	9,346	9,659
Accounts payable and other liabilities	28,835	262
Net cash provided by operating activities	221,045	157,751
Cash flows from investing activities:
Purchases of property, equipment and other	(33,768)	(9,925)
Purchases of investments	(688,903)	(433,154)
Proceeds from maturities and sales of investments	714,081	548,973
Net cash (used in) provided by investing activities	(8,590)	105,894
Cash flows from financing activities:
Proceeds from issuance of common stock under equity incentive plans	15,487	17,938
Taxes paid related to net share settlement of equity awards	(9,413)	(20,941)
Net cash provided by (used in) financing activities	6,074	(3,003)
Net increase in cash, cash equivalents and restricted cash equivalents	218,529	260,642
Cash, cash equivalents and restricted cash equivalents at beginning of period	320,772	268,137
Cash, cash equivalents and restricted cash equivalents at end of period	539,301	528,779
Non-cash operating activities:
Right-of-use assets obtained in exchange for lease obligations	4,893	1,824
Non-cash investing activities:
Unpaid liabilities incurred for purchases of property and equipment	5,125	804
Unpaid liabilities incurred in asset acquisition	9,000	0
Unpaid liabilities incurred for unsettled investment purchases	$ 7,378	$ 0

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	6 Months Ended
	Jul. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization Exelixis, Inc. (Exelixis, we, our or us) is an oncology-focused biotechnology company that strives to accelerate the discovery, development and commercialization of new medicines for difficult-to-treat cancers. We have invented and brought to market novel, effective and tolerable therapies using our drug discovery and development resources and capabilities and commercialization platform; we will continue to build on this foundation, working toward providing cancer patients with additional treatment options. Since we were founded in 1994, four products resulting from our discovery efforts have progressed through clinical development, received regulatory approval and established a commercial presence in various geographies around the world. Our flagship molecule, cabozantinib, is an inhibitor of multiple tyrosine kinases including MET, AXL, VEGF receptors and RET and has been approved by the U.S. Food and Drug Administration (FDA) and foreign regulatory authorities as two products: CABOMETYX® (cabozantinib) tablets approved for advanced renal cell carcinoma (RCC), both alone and in combination with Bristol Myers Squibb Company’s OPDIVO® (nivolumab), and for previously treated hepatocellular carcinoma (HCC); and COMETRIQ® (cabozantinib) capsules approved for progressive, metastatic medullary thyroid cancer (MTC). For these types of cancer, cabozantinib has become or is becoming a standard of care. The other two products resulting from our discovery efforts are: COTELLIC® (cobimetinib), an inhibitor of MEK, approved as part of multiple combination regimens to treat specific forms of advanced melanoma and marketed under a collaboration with Genentech, Inc. (a member of the Roche Group) (Genentech); and MINNEBRO® (esaxerenone), an oral, non-steroidal, selective blocker of the mineralocorticoid receptor, approved for the treatment of hypertension in Japan and licensed to Daiichi Sankyo Company, Limited (Daiichi Sankyo). Leveraging the revenue stream derived from our cabozantinib franchise and other marketed products, we are expanding our oncology product pipeline through drug discovery efforts, which encompass both small molecule and biologics programs with multiple modalities and mechanisms of action. Basis of Presentation The accompanying Condensed Consolidated Financial Statements include the accounts of Exelixis and those of our wholly-owned subsidiaries. These entities’ functional currency is the U.S. dollar. All intercompany balances and transactions have been eliminated. The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the U.S. for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In our opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of our financial statements for the periods presented have been included. Operating results for the six months ended June 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021 or for any future period. The accompanying Condensed Consolidated Financial Statements and Notes thereto should be read in conjunction with our Consolidated Financial Statements and Notes thereto for the year ended December 31, 2020, included in our Annual Report on Form 10-K submitted to the SEC on February 10, 2021. We have adopted a 52- or 53-week fiscal year policy that generally ends on the Friday closest to December 31 st . Fiscal year 2021, which is a 52-week fiscal year, will end on December 31, 2021 and fiscal year 2020, which was a 52-week fiscal year, ended on January 1, 2021. For convenience, references in this report as of and for the fiscal periods ended July 2, 2021 and July 3, 2020, and as of and for the fiscal year ended January 1, 2021, are indicated as being as of and for the fiscal periods ended June 30, 2021 and June 30, 2020, and the year ended December 31, 2020, respectively. Segment Information We operate in one business segment that focuses on the discovery, development and commercialization of new medicines for difficult-to-treat cancers. Our Chief Executive Officer, as the chief operating decision-maker, manages and allocates resources to our operations on a total consolidated basis. Consistent with this decision-making process, our Chief Executive Officer uses consolidated, single-segment financial information for purposes of evaluating performance, forecasting future period financial results, allocating resources and setting incentive targets. All of our long-lived assets are located in the U.S. See “Note 2. Revenues” for enterprise-wide disclosures about product sales, revenues from major customers and revenues by geographic region. Use of Estimates The preparation of the accompanying Condensed Consolidated Financial Statements conforms to accounting principles generally accepted in the U.S., which requires management to make judgments, estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosures. On an ongoing basis, we evaluate our significant estimates. We base our estimates on historical experience and on various other market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates. Reclassifications Certain prior period amounts in the accompanying Condensed Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported total revenues, income from operations, net income, total assets, total liabilities or total stockholders’ equity. Significant Accounting Policies Except for the foreign currency forward contracts for non-designated hedges, there have been no material changes to our significant accounting policies during the six months ended June 30, 2021 , as compared to the significant accounting policies disclosed in Note 1 – Significant Accounting Policies included in our Annual Report on Form 10-K for the year ended December 31, 2020. Foreign Currency Forward Contracts for Non-Designated Hedges We may use forward foreign currency exchange contracts (forward contracts) to hedge certain operational exposures resulting from potential changes in foreign currency exchange rates. Our strategy is to enter into forward contracts so that increases or decreases in our foreign currency exposures are offset by gains or losses on the foreign currency forward contracts thereby mitigating the risks and volatility associated with our foreign currency transactions. We do not apply hedge accounting treatment to these non-designated hedging instruments. We do not hold or issue derivative instruments for trading or speculative purposes. Our forward contracts are generally short-term in duration. Given the short duration of the forward contracts, amounts recorded generally are not significant. We account for our derivative instruments as either assets or liabilities on our Condensed Consolidated Balance Sheets and measure them at fair value. Derivatives not designated as hedging instruments are adjusted to fair value through earnings in other income (expense), net in the Condensed Consolidated Statements of Income. Recently Adopted Accounting Pronouncements On January 1, 2021, we adopted the Accounting Standards Board’s (FASB) Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740)-Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Accounting Standards Codification (ASC) Topic 740, Income Taxes and clarifying and amending existing guidance. Our adoption of ASU 2019-12 did not have a significant impact on the accompanying Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted There were no new accounting pronouncements issued since our filing of the Annual Report on Form 10-K for the year ended December 31, 2020, which could have a significant effect on our condensed consolidated financial statements.

Revenues

Revenues	6 Months Ended
	Jul. 02, 2021
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenues consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Product revenues: Gross product revenues $ 380,204 $ 229,898 $ 694,409 $ 482,464 Discounts and allowances (95,956) (51,168) (182,949) (109,854) Net product revenues 284,248 178,730 511,460 372,610 Collaboration revenues: License revenues 39,640 59,234 67,168 80,113 Collaboration services revenues 61,289 21,515 76,779 33,671 Total collaboration revenues 100,929 80,749 143,947 113,784 Total revenues $ 385,177 $ 259,479 $ 655,407 $ 486,394 The percentage of total revenues by customer who individually accounted for 10% or more of our total revenues were as follows: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Ipsen Pharma SAS 24 % 20 % 19 % 17 % Affiliates of McKesson Corporation 14 % 11 % 14 % 13 % Affiliates of CVS Health Corporation 13 % 13 % 14 % 15 % Affiliates of AmerisourceBergen Corporation 12 % 11 % 13 % 11 % Affiliates of Optum Specialty Pharmacy 8 % 10 % 9 % 11 % Accredo Health, Incorporated 8 % 10 % 8 % 9 % Takeda Pharmaceutical Company Limited 2 % 10 % 2 % 5 % The percentage of trade receivables by customer who individually accounted for 10% or more of our trade receivables were as follows: June 30, 2021 December 31, 2020 Ipsen Pharma SAS 24 % 23 % Affiliates of McKesson Corporation 21 % 12 % Affiliates of AmerisourceBergen Corporation 19 % 11 % Affiliates of CVS Health Corporation 13 % 11 % Takeda Pharmaceutical Company Limited 4 % 10 % Revenues by geographic region were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 U.S. $ 287,190 $ 181,231 $ 517,147 $ 377,827 Europe 90,921 52,917 124,727 81,953 Japan 7,066 25,331 13,533 26,614 Total revenues $ 385,177 $ 259,479 $ 655,407 $ 486,394 Total revenues include net product revenues attributed to geographic regions based on the ship-to location and license and collaboration services revenues attributed to geographic regions based on the location of our collaboration partners’ headquarters. Net product revenues and license revenues are recorded in accordance with ASC Topic 606, Revenue from Contracts with Customers (Topic 606). License revenues include the recognition of the portion of milestones payments allocated to the transfer of intellectual property licenses for which it had become probable in the current period that the milestone would be achieved and a significant reversal of revenues would not occur, as well as royalty revenues and our share of profits under our collaboration agreement with Genentech. Collaboration services revenues were recorded in accordance with ASU 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 and by analogy to Topic 606. Collaboration services revenues include the recognition of deferred revenues for the portion of upfront and milestone payments allocated to our research and development services performance obligations, development cost reimbursements earned under our collaboration agreements, product supply revenues, net of product supply costs, and the royalties we paid on sales of products containing cabozantinib by our collaboration partners. We received notification that, effective January 1, 2021, Royalty Pharma plc (Royalty Pharma) acquired from GlaxoSmithKline (GSK) all rights, title and interest in royalties on net product sales containing cabozantinib for non-U.S. markets for the full term of the royalty and for the U.S. market through September 2026, after which time U.S. royalties will revert back to GSK. Net product revenues by product were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 CABOMETYX $ 275,614 $ 173,610 $ 499,209 $ 362,826 COMETRIQ 8,634 5,120 12,251 9,784 Net product revenues $ 284,248 $ 178,730 $ 511,460 $ 372,610 Product Sales Discounts and Allowances The activities and ending reserve balances for each significant category of discounts and allowances, which constitute variable consideration, were as follows (in thousands): Chargebacks, Discounts for Prompt Payment and Other Other Customer Credits/Fees and Co-pay Assistance Rebates Total Balance at December 31, 2020 $ 9,853 $ 3,279 $ 17,404 $ 30,536 Provision related to sales made in: Current period 114,489 15,392 51,355 181,236 Prior periods (40) (164) 1,917 1,713 Payments and customer credits issued (108,487) (11,637) (46,349) (166,473) Balance at June 30, 2021 $ 15,815 $ 6,870 $ 24,327 $ 47,012 The allowance for chargebacks, discounts for prompt payment and other are recorded as a reduction of trade receivables, net and the remaining reserves are recorded as rebates and fees due to customers in the accompanying Condensed Consolidated Balance Sheets. Contract Assets and Liabilities We receive payments from our collaboration partners based on billing schedules established in each contract. Amounts are recorded as accounts receivable when our right to consideration is unconditional. We may also recognize revenue in advance of the contractual billing schedule and such amounts are recorded as a contract asset when recognized. We may be required to defer recognition of revenue for upfront and milestone payments until we perform our obligations under these arrangements, and such amounts are recorded as deferred revenue upon receipt or when due. For those contracts that have multiple performance obligations, contract assets and liabilities are reported on a net basis at the contract level. Contract assets and liabilities were as follows (in thousands): June 30, 2021 December 31, 2020 Contract assets Current portion (1) $ 9,749 $ — Long-term portion (1) 948 — Total contract assets $ 10,697 $ — Contract liabilities: Current portion (2) $ 6,314 $ 1,790 Long-term portion (2) 8,577 3,755 Total contract liabilities $ 14,891 $ 5,545 ____________________ (1) Presented in prepaid and other current assets and other long-term assets, respectively, on the accompanying Condensed Consolidated Balance Sheets. (2) Presented in other current liabilities and long-term portion of deferred revenues, respectively, in the accompanying Condensed Consolidated Balance Sheets. Contract assets as of June 30, 2021 are primarily related to a $12.5 million development milestone that we deemed probable of achievement and recognized $11.8 million of revenues during the three months ended June 30, 2021. Contract liabilities as of June 30, 2021 are primarily related to deferred revenues from Takeda Pharmaceutical Company Limited (Takeda). During the six months ended June 30, 2021 and 2020, we recognized $4.8 million and $3.4 million, respectively, in revenues that were included in the beginning deferred revenues balance for those periods. During the three and six months ended June 30, 2021, we recognized $40.6 million and $67.8 million, respectively, in revenues for performance obligations satisfied in previous periods, as compared to $62.0 million and $82.2 million for the corresponding periods in 2020. Such revenues were primarily related to royalty payments allocated to the license performance obligations for our collaborations with Ipsen Pharma SAS (Ipsen), Takeda, Daiichi Sankyo and Genentech. As of June 30, 2021 , $86.9 million of t he combined transaction prices for our Ipsen and Takeda collaborations were allocated to performance obligations that had not yet been satisfied. See “Note 3. Collaboration Agreements— Cabozantinib Collaborations - Performance Obligations and Transaction Prices for our Ipsen and Takeda Collaborations” to our Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2020 for information about the expected timing to satisfy these performance obligations.

Collaboration Agreements, In-Li

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities	6 Months Ended
	Jul. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
COLLABORATION AGREEMENTS, IN-LICENSING ARRANGEMENTS AND BUSINESS DEVELOPMENT ACTIVITIES	COLLABORATION AGREEMENTS, IN-LICENSING ARRANGEMENTS AND BUSINESS DEVELOPMENT ACTIVITIES We have established multiple collaborations with leading pharmaceutical companies for the commercialization and further development of our cabozantinib franchise. Additionally, we have entered into several research collaborations and in-licensing arrangements to further enhance our early-stage pipeline and expand our ability to discover, develop and commercialize novel therapies with the goal of providing new treatment options for cancer patients and their physicians. We also entered into other collaborations with leading pharmaceutical companies for other compounds and programs in our portfolio. See “Note 3. Collaboration Agreements” to our Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2020, or as further described below, for additional information on each of our collaboration agreements and in-licensing arrangements. Cabozantinib Collaborations Ipsen Collaboration In February 2016, we entered into a collaboration agreement with Ipsen for the commercialization and further development of cabozantinib. Under the terms of the collaboration agreement, as amended, Ipsen received exclusive commercialization rights for current and potential future cabozantinib indications outside of the U.S. and Japan. We have also agreed to collaborate with Ipsen on the development of cabozantinib for current and potential future indications. The parties’ efforts are governed through a joint steering committee and appropriate subcommittees established to guide and oversee the collaboration’s operation and strategic direction; provided, however, that we retain final decision-making authority with respect to cabozantinib’s ongoing development. During the second quarter of 2021, Ipsen opted into and is now co-funding the development costs for COSMIC-311, our phase 3 pivotal trial evaluating cabozantinib versus placebo in patients with radioactive iodine differentiated thyroid cancer who have progressed after up to two VEGF receptor-targeted therapies. Under the terms of the Agreement, Ipsen is now obligated to reimburse us for their share of the COSMIC-311 global development costs, as well as an additional payment calculated as a percentage of such costs, triggered by the timing of the exercise of its option. We determined that the decision to opt into and co-fund the development costs for COSMIC-311 represented a contract modification for additional distinct services at their standalone selling price and therefore was treated as a separate contract under Topic 606. Accordingly, collaboration services revenues for the three and six months ended June 30, 2021, includes a cumulative catch up for Ipsen’s share of global development costs incurred since the beginning of the study and through the end of the period. Revenues under the collaboration agreement with Ipsen were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 License revenues $ 33,656 $ 33,597 $ 56,107 $ 51,546 Collaboration services revenues 57,265 19,320 68,620 30,407 Total $ 90,921 $ 52,917 $ 124,727 $ 81,953 As of June 30, 2021 , $46.2 million of the tr ansaction price was allocated to our research and development services performance obligations that has not yet been satisfied. Takeda Collaboration In January 2017, we entered into a collaboration and license agreement with Takeda for the commercialization and further development of cabozantinib. Pursuant to this collaboration and license agreement, as amended, Takeda has exclusive commercialization rights for current and potential future cabozantinib indications in Japan, and the parties have agreed to collaborate on the clinical development of cabozantinib in Japan. The operation and strategic direction of the parties’ collaboration is governed through a joint executive committee and appropriate subcommittees. Revenues under the collaboration agreement with Takeda were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 License revenues $ 2,097 $ 22,946 $ 3,398 $ 22,946 Collaboration services revenues 4,024 2,195 8,159 3,264 Total $ 6,121 $ 25,141 $ 11,557 $ 26,210 As of June 30, 2021, $40.7 million of the transaction price was allocated to our research and development services performance obligations that has not yet been satisfied. GSK and Royalty Pharma In October 2002, we established a product development and commercialization collaboration agreement with GSK, that required us to pay a 3% royalty to GSK on the worldwide net sales of any product incorporating cabozantinib by us and our collaboration partners. As disclosed in Note 2, we received notification that, effective January 1, 2021, Royalty Pharma acquired from GSK all rights, title and interest in royalties on net product sales containing cabozantinib for non-U.S. markets for the full term of the royalty and for U.S. market through September 2026, after which time U.S. royalties will revert back to GSK. Royalties earned by GSK and Royalty Pharma in connection with our sales of cabozantinib are included in cost of goods sold and as a reduction of collaboration services revenues for sales by our collaboration partners. Such royalties were $12.1 million and $22.2 million during the three and six months ended June 30, 2021, respectively, as compared to $7.6 million and $15.7 million in the corresponding periods in 2020. Genentech Collaboration In December 2006, we out-licensed the development and commercialization of cobimetinib to Genentech under a worldwide collaboration agreement. In November 2015, the FDA approved cobimetinib, under the brand name COTELLIC, in combination with Genentech’s ZELBORAF® (vemurafenib) for the treatment of patients with BRAF V600E or V600K mutation-positive advanced melanoma. COTELLIC in combination with ZELBORAF has also been approved in the European Union and multiple additional countries for use in the same indication. In July 2020, the FDA also approved COTELLIC for use in combination with ZELBORAF and TECENTRIQ® (atezolizumab) for the treatment of patients with BRAF V600 mutation-positive advanced melanoma in previously untreated patients. License revenues under the collaboration agreement with Genentech were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Profits on U.S. commercialization $ 2,160 $ 1,376 $ 3,954 $ 2,783 Royalty revenues on ex-U.S. sales $ 782 $ 1,125 $ 1,733 $ 2,434 Research Collaborations, In-Licensing Arrangements and Other Business Development Activities During the six months ended June 30, 2021, in support of our development pipeline, we entered into additional collaboration and in-licensing arrangements with Adagene, Inc. (Adagene) and WuXi Biologics Ireland Limited (WuXi Bio), and amended our existing collaboration agreement with StemSynergy Therapeutics, Inc. (StemSynergy). In conjunction with each of these arrangements we have made aggregate upfront payments totaling $17.0 million and will make payments for potential future development milestones of up to $58.5 million, regulatory milestones of up to $139.0 million and commercial milestones of up to $377.5 million, each in the aggregate per product, as well as royalties on future net product sales. Additionally, we entered into an asset purchase agreement with GamaMabs Pharma SA (GamaMabs), pursuant to which we made an upfront payment of $5.0 million for the initial technology transfer, and subject to certain conditions, will make a $9.0 million payment upon closing of the transaction. We will also make payments for potential future development milestones of up to $42.0 million and regulatory milestones of up to $22.5 million, per product.

Cash and Investments

Cash and Investments	6 Months Ended
	Jul. 02, 2021
Investments, Debt and Equity Securities [Abstract]
CASH AND INVESTMENTS	CASH AND INVESTMENTS Cash, Cash Equivalents and Restricted Cash Equivalents A reconciliation of cash, cash equivalents, and restricted cash equivalents reported in the accompanying Condensed Consolidated Balance Sheets to the amount reported within the accompanying Condensed Consolidated Statements of Cash Flows was as follows (in thousands): June 30, 2021 December 31, 2020 Cash and cash equivalents $ 492,462 $ 319,217 Restricted cash equivalents included in other long-term assets 46,839 1,555 Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows $ 539,301 $ 320,772 Restricted cash equivalents are used to collateralize letters of credit and consist of money-market funds and certificates of deposit with original maturities of 90 days or less. The restricted cash equivalents are classified as other long-term assets based upon the remaining term of the underlying restriction. As of June 30, 2021, restricted cash equivalents included $45.3 million of short-term investments, which is collateral under our January 2021 standby letter of credit to guarantee our obligation to fund a portion of the total tenant improvements related to our build-to-suit lease at our corporate campus. As we fund these tenant improvements, our restricted cash becomes available for operations. Cash, Cash Equivalents, Restricted Cash Equivalents and Investments Cash, cash equivalents, restricted cash equivalents and investments consisted of the following (in thousands): June 30, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 716,916 $ 141 $ — $ 717,057 Corporate bonds 489,678 2,630 (166) 492,142 U.S. Treasury and government-sponsored enterprises 132,036 43 (13) 132,066 Municipal bonds 14,261 41 (4) 14,298 Total debt securities available-for-sale 1,352,891 2,855 (183) 1,355,563 Cash 88,511 — — 88,511 Money market funds 179,306 — — 179,306 Certificates of deposit 115,706 — — 115,706 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,736,414 $ 2,855 $ (183) $ 1,739,086 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 569,456 $ 372 $ — $ 569,828 Corporate bonds 543,520 5,244 (7) 548,757 U.S. Treasury and government-sponsored enterprises 208,326 232 (4) 208,554 Municipal bonds 28,680 83 (1) 28,762 Total debt securities available-for-sale 1,349,982 5,931 (12) 1,355,901 Cash 82,176 — — 82,176 Money market funds 40,761 — — 40,761 Certificates of deposit 60,004 — — 60,004 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,532,923 $ 5,931 $ (12) $ 1,538,842 Interest receivable was $3.3 million and $4.5 million as of June 30, 2021 and December 31, 2020, respectively, and is included in prepaid expenses and other current assets in the accompanying Condensed Consolidated Balance Sheets. Realized gains and losses on the sales of investments were insignificant during the three and six months ended June 30, 2021 and 2020. We manage credit risk associated with our investment portfolio through our investment policy, which limits purchases to high-quality issuers and limits the amount of our portfolio that can be invested in a single issuer. The fair value and gross unrealized losses on debt securities available-for-sale in an unrealized loss position were as follows (in thousands): June 30, 2021 Fair Value Gross Unrealized Losses Commercial paper $ 1,002 $ — Corporate bonds 154,767 (166) U.S. Treasury and government-sponsored enterprises 38,088 (13) Municipal bonds 5,897 (4) Total $ 199,754 $ (183) December 31, 2020 Fair Value Gross Unrealized Losses Corporate bonds $ 28,445 $ (7) U.S. Treasury and government-sponsored enterprises 21,989 (4) Municipal bonds 5,865 (1) Total $ 56,299 $ (12) All securities presented have been in an unrealized loss position for less than 12 months. There were 53 and 14 investments in an unrealized loss position as of June 30, 2021 and December 31, 2020, respectively. During the six months ended June 30, 2021 and 2020, we did not record an allowance for credit losses or other impairment charges on our investment securities. Based upon our quarterly impairment review, we determined that the unrealized losses were not attributed to credit risk but were primarily associated with changes in interest rates and market liquidity. Based on the scheduled maturities of our investments, we determined that it was more likely than not that we will hold these investments for a period of time sufficient for a recovery of our cost basis. The fair value of debt securities available-for-sale by contractual maturity was as follows (in thousands): June 30, 2021 December 31, 2020 Maturing in one year or less $ 1,015,650 $ 1,034,150 Maturing after one year through five years 339,913 321,751 Total debt securities available-for-sale $ 1,355,563 $ 1,355,901

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jul. 02, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value reflects the amounts that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy has the following three levels: • Level 1 - quoted prices (unadjusted) in active markets for identical assets and liabilities; • Level 2 - inputs other than level 1 that are observable either directly or indirectly, such as quoted prices in active markets for similar instruments or on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets; • Level 3 - unobservable inputs that are supported by little or no market activity that are significant to the fair value measurement The classifications within the fair value hierarchy of our financial assets that were measured and recorded at fair value on a recurring basis were as follows (in thousands): June 30, 2021 Level 1 Level 2 Total Commercial paper $ — $ 717,057 $ 717,057 Corporate bonds — 492,142 492,142 U.S. Treasury and government-sponsored enterprises — 132,066 132,066 Municipal bonds — 14,298 14,298 Total debt securities available-for-sale — 1,355,563 1,355,563 Money market funds 179,306 — 179,306 Certificates of deposit — 115,706 115,706 Total financial assets carried at fair value $ 179,306 $ 1,471,269 $ 1,650,575 December 31, 2020 Level 1 Level 2 Total Commercial paper $ — $ 569,828 $ 569,828 Corporate bonds — 548,757 548,757 U.S. Treasury and government-sponsored enterprises — 208,554 208,554 Municipal bonds — 28,762 28,762 Total debt securities available-for-sale — 1,355,901 1,355,901 Money market funds 40,761 — 40,761 Certificates of deposit — 60,004 60,004 Total financial assets carried at fair value $ 40,761 $ 1,415,905 $ 1,456,666 When available, we value investments based on quoted prices for those financial instruments, which is a Level 1 input. Our remaining investments are valued using third-party pricing sources, which use observable market prices, interest rates and yield curves observable at commonly quoted intervals for similar assets as observable inputs for pricing, which is a Level 2 input. The carrying amount of our remaining financial assets and liabilities, which include cash, receivables and payables, approximate their fair values due to their short-term nature. Forward Foreign Currency Contracts In January 2021, we initiated an operational hedging program and entered into forward contracts to hedge certain operational exposures for the changes in foreign currency exchanges rates associated with assets or liabilities denominated in foreign currencies, primarily the Euro. As of June 30, 2021, we had one forward contract outstanding to sell €9.3 million. The forward contract has a maturity of three months, is recorded at fair value and is included in prepaid expenses and other current assets in the Condensed Consolidated Balance Sheets. The unrealized gain/loss on the settlement of the forward contract is not material as of June 30, 2021. The forward contract is considered a Level 2 in the fair value hierarchy of our fair value measurements. For the six months ended June 30, 2021, we recognized $0.3 million net gains on the maturity of our forward contracts, which is included in other income (expense), net on our Condensed Consolidated Statements of Income.

Inventory

Inventory	6 Months Ended
	Jul. 02, 2021
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory consisted of the following (in thousands): June 30, 2021 December 31, 2020 Raw materials $ 6,905 $ 7,773 Work in process 25,951 20,610 Finished goods 8,587 7,291 Total $ 41,443 $ 35,674 Balance Sheet classification: Current portion included in inventory $ 24,982 $ 20,973 Long-term portion included in other long-term assets 16,461 14,701 Total $ 41,443 $ 35,674 Write-downs related to excess and expiring inventory were $2.3 million and $1.3 million for the six months ended June 30, 2021 and 2020, respectively.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jul. 02, 2021
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION We allocated the stock-based compensation expense for our equity incentive plans and our Employee Stock Purchase Plan (ESPP) as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Research and development $ 13,667 $ 6,112 $ 26,063 $ 11,198 Selling, general and administrative 14,368 10,042 36,625 18,938 Total stock-based compensation expense $ 28,035 $ 16,154 $ 62,688 $ 30,136 Stock-based compensation for each type of award under our equity incentive plans and ESPP were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Stock options $ 5,902 $ 5,301 $ 10,596 $ 10,295 Restricted stock units 15,412 8,599 27,081 16,396 Performance stock units 4,698 1,429 22,645 1,925 ESPP 2,023 825 2,366 1,520 Total stock-based compensation expense $ 28,035 $ 16,154 $ 62,688 $ 30,136 As of June 30, 2021 , 8,254,455 sh ares were available for grant under the Exelixis, Inc. 2017 Equity Incentive Plan (as amended and restated, the 2017 Plan). The share reserve is reduced by 1 share for each share issued pursuant to a stock option and 1.5 shares for full value awards granted in the form of restricted stock units (RSUs). During the six months ended June 30, 2021, we granted 1,733,554 stock options with a weighted average exercise price of $22.50 per share and a weighted average grant date fair value of $9.70 per s hare. As of June 30, 2021, there were 15,443,578 stock options outstanding and $32.2 million of related unrecognized compensation expense. During the six months ended June 30, 2021, we granted 3,575,190 service-based RSUs with a weighted average grant date fair value of $21.76 per share. As of June 30, 2021, there were 8,314,774 RSUs outstanding and $149.0 million of related unrecognized compensation expense. Stock options and RSUs granted to employees during the six months ended June 30, 2021 have vesting conditions and contractual lives of a similar nature to those described in “Note 8. Employee Benefit Plans” of the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020. In March 2021, we awarded 1,027,650 (the target amount) performance-based (PSUs), subject to a performance and a market condition (the 2021 PSUs). Pursuant to the terms of 2021 PSUs, the holders of the awards may earn up to 200% of the target amount of shares, depending on the level of achievement of the performance condition related to certain net product revenues and a total shareholder return (TSR) market condition. The TSR market condition is based on our relative TSR percentile rank compared to companies in the NASDAQ Biotechnology Index during the performance period, which is January 2, 2021 through December 29, 2023. Fifty percent of the shares earned subject to the performance and market conditions will vest at the end of the performance period and the remainder will vest approximately one year later subject to employee’s continuous service. The 2021 PSUs will be forfeited if the performance condition at or above a threshold level is not achieved by December 29, 2023. A Monte Carlo simulation model was used to determine the grant date fair value of $24.54 for the 2021 PSUs based on the following assumptions: Fair value of the Company’s common stock on grant date $ 21.31 Expected volatility 49 % Risk-free interest rate 0.29 % Dividend yield — % The Monte Carlo simulation model also assumed correlations of returns of the stock prices of the Company’s common stock and the common stock of a peer group of companies and historical stock price volatility of the peer group of companies. The valuation model also used terms based on the length of the performance period and compound annual growth rate goals for total stockholder return based on the provisions of the award. As of June 30, 2021, there were 8,709,765 PSUs outstanding and $155.7 million of related unrecognized compensation expense. Expense recognition for PSUs commences when it is determined that achievement of the performance target is probable. For more information about our PSUs, see “Note 8. Employee Benefit Plans” of the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020.

Provision For Income Taxes

Provision For Income Taxes	6 Months Ended
	Jul. 02, 2021
Income Tax Disclosure [Abstract]
PROVISION FOR INCOME TAXES	PROVISION FOR INCOME TAXESThe effective tax rate for the three and six months ended June 30, 2021 was 23.1% and 20.5%, respectively, as compared to 17.2% and 18.0% for the corresponding periods in 2020. The effective tax rate for the three and six months ended June 30, 2021 and 2020 differed from the U.S. federal statutory tax rate of 21% primarily due to excess tax benefits related to the exercise of certain stock options during the periods and the generation of federal tax credits, partially offset by state taxes.

Net Income Per Share

Net Income Per Share	6 Months Ended
	Jul. 02, 2021
Earnings Per Share [Abstract]
NET INCOME PER SHARE	NET INCOME PER SHARE Net income per share - basic and diluted, were computed as follows (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Numerator: Net income $ 96,092 $ 66,821 $ 97,693 $ 115,433 Denominator: Weighted-average common shares outstanding — basic 314,117 307,807 313,295 306,598 Dilutive securities 8,824 10,337 8,819 10,394 Weighted-average common shares outstanding — diluted 322,941 318,144 322,114 316,992 Net income per share — basic $ 0.31 $ 0.22 $ 0.31 $ 0.38 Net income per share — diluted $ 0.30 $ 0.21 $ 0.30 $ 0.36 Dilutive securities included outstanding stock options and Performance Stock Options, unvested RSUs and PSUs and ESPP contributions. Certain potential common shares were excluded from our calculation of weighted-average common shares outstanding - diluted because either they would have had an anti-dilutive effect on net income per share or they were related to shares from PSUs that were contingently issuable and the contingency had not been satisfied at the end of the reporting period. The weighted-average potential common shares excluded from our calculation were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Anti-dilutive securities and contingently issuable shares excluded 12,285 8,812 11,146 10,413

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jul. 02, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIESIn September 2019, we received a notice letter regarding an Abbreviated New Drug Application (ANDA) submitted to the FDA by MSN Pharmaceuticals, Inc. (MSN), requesting approval to market a generic version of CABOMETYX tablets. MSN’s initial notice letter included a Paragraph IV certification with respect to our U.S. Patent Nos. 8,877,776, 9,724,342, 10,034,873 and 10,039,757, which are listed in the Approved Drug Products with Therapeutic Equivalence Evaluations, also referred to as the Orange Book. MSN’s initial notice letter did not provide a Paragraph IV certification against U.S. Patent No. 7,579,473, the composition of matter patent, or U.S. Patent No. 8,497,284, a method of use patent. On October 29, 2019, we filed a complaint in the United States District Court for the District of Delaware (the Delaware District Court) for patent infringement against MSN asserting U.S. Patent No. 8,877,776 arising from MSN’s ANDA filing with the FDA. On November 20, 2019, MSN filed its response to the complaint, alleging that U.S. Patent No. 8,877,776 is invalid and not infringed. On May 5, 2020, we received notice from MSN that it had amended its ANDA to assert additional Paragraph IV certifications. The ANDA now requests approval to market a generic version of CABOMETYX tablets prior to expiration of the two previously unasserted CABOMETYX patents: U.S. Patent No. 7,579,473 and U.S. Patent No. 8,497,284. On May 11, 2020, we filed a complaint in the Delaware District Court for patent infringement against MSN asserting U.S. Patent No. 7,579,473 and U.S. Patent No. 8,497,284 arising from MSN’s amended ANDA filing with the FDA. Neither of our complaints alleges infringement of U.S. Patent Nos. 9,724,342, 10,034,873 and 10,039,757. On May 22, 2020, MSN filed its response to the complaint, alleging that each of U.S. Patent No. 7,579,473 and U.S. Patent No. 8,497,284 is invalid and not infringed. On March 23, 2021, MSN filed its First Amended Answer and Counterclaims (amending its prior filing from May 22, 2020), seeking, among other things, a declaratory judgment that U.S. Patent No. 9,809,549 is invalid and would not be infringed by MSN if its generic version of CABOMETYX tablets were approved by the FDA. On April 7, 2021, we filed our response to MSN’s First Amended Answer and Counterclaims, denying, among other things, that U.S. Patent No. 9,809,549 is invalid or would not be infringed. In our complaints, we are seeking, among other relief, an order that the effective date of any FDA approval of MSN’s ANDA would be a date no earlier than the expiration of all of U.S. Patent No. 7,579,473, U.S. Patent No. 8,497,284 and U.S. Patent No. 8,877,776, the latest of which expires on October 8, 2030, and equitable relief enjoining MSN from infringing these patents. These lawsuits against MSN have been consolidated, and a bench trial has been scheduled for May 2022. In May 2021, we received notice letters from Teva Pharmaceuticals Development, Inc. and Teva Pharmaceuticals USA, Inc. (individually and collectively referred to as Teva) regarding an ANDA Teva submitted to the FDA, requesting approval to market a generic version of CABOMETYX tablets. Teva’s notice letters included a Paragraph IV certification with respect to our U.S. Patent Nos. 9,724,342 (formulations), 10,034,873 (methods of treatment) and 10,039,757 (methods of treatment), which are listed in the Orange Book and expire in 2033, 2031 and 2031, respectively. Teva’s notice letters did not provide a Paragraph IV certification against any additional CABOMETYX patents. On June 17, 2021, we filed a complaint in the Delaware District Court for patent infringement against Teva, along with Teva Pharmaceutical Industries Limited, asserting U.S. Patent Nos. 9,724,324 (formulations), 10,034,873 (methods of treatment) and 10,039,757 (methods of treatment) arising from Teva’s ANDA filing with the FDA. We are seeking, among other relief, an order that the effective date of any FDA approval of Teva’s ANDA would be a date no earlier than the expiration of all of U.S. Patent Nos. 9,724,342, 10,034,873 and 10,039,757, the latest of which expires on July 9, 2033, and equitable relief enjoining Teva and Teva Pharmaceutical Industries Limited from infringing these patents. The sale of any generic version of CABOMETYX earlier than its patent expiration could significantly decrease our revenues derived from the U.S. sales of CABOMETYX and thereby materially harm our business, financial condition and results of operations. It is not possible at this time to determine the likelihood of an unfavorable outcome or estimate of the amount or range of any potential loss. We may also from time to time become a party or subject to various other legal proceedings and claims, either asserted or unasserted, which arise in the ordinary course of business. Some of these proceedings have involved, and may involve in the future, claims that are subject to substantial uncertainties and unascertainable damages.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jul. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Consolidation	The accompanying Condensed Consolidated Financial Statements include the accounts of Exelixis and those of our wholly-owned subsidiaries. These entities’ functional currency is the U.S. dollar. All intercompany balances and transactions have been eliminated.
Basis of Presentation	The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the U.S. for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In our opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of our financial statements for the periods presented have been included. Operating results for the six months ended June 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021 or for any future period. The accompanying Condensed Consolidated Financial Statements and Notes thereto should be read in conjunction with our Consolidated Financial Statements and Notes thereto for the year ended December 31, 2020, included in our Annual Report on Form 10-K submitted to the SEC on February 10, 2021.
Fiscal Period	We have adopted a 52- or 53-week fiscal year policy that generally ends on the Friday closest to December 31 st
Segment Information	Segment Information We operate in one business segment that focuses on the discovery, development and commercialization of new medicines for difficult-to-treat cancers. Our Chief Executive Officer, as the chief operating decision-maker, manages and
Use of Estimates	Use of Estimates The preparation of the accompanying Condensed Consolidated Financial Statements conforms to accounting principles generally accepted in the U.S., which requires management to make judgments, estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosures. On an ongoing basis, we evaluate our significant estimates. We base our estimates on historical experience and on various other market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates.
Reclassifications	ReclassificationsCertain prior period amounts in the accompanying Condensed Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported total revenues, income from operations, net income, total assets, total liabilities or total stockholders’ equity.
Foreign Currency Forward Contracts for Non-Designated Hedges	Foreign Currency Forward Contracts for Non-Designated Hedges We may use forward foreign currency exchange contracts (forward contracts) to hedge certain operational exposures resulting from potential changes in foreign currency exchange rates. Our strategy is to enter into forward contracts so that increases or decreases in our foreign currency exposures are offset by gains or losses on the foreign currency forward contracts thereby mitigating the risks and volatility associated with our foreign currency transactions. We do not apply hedge accounting treatment to these non-designated hedging instruments. We do not hold or issue derivative instruments for trading or speculative purposes. Our forward contracts are generally short-term in duration. Given the short duration of the forward contracts, amounts recorded generally are not significant. We account for our derivative instruments as either assets or liabilities on our Condensed Consolidated Balance Sheets and measure them at fair value. Derivatives not designated as hedging instruments are adjusted to fair value through earnings in other income (expense), net in the Condensed Consolidated Statements of Income.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements On January 1, 2021, we adopted the Accounting Standards Board’s (FASB) Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740)-Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Accounting Standards Codification (ASC) Topic 740, Income Taxes and clarifying and amending existing guidance. Our adoption of ASU 2019-12 did not have a significant impact on the accompanying Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted There were no new accounting pronouncements issued since our filing of the Annual Report on Form 10-K for the year ended December 31, 2020, which could have a significant effect on our condensed consolidated financial statements.
Revenues	Total revenues include net product revenues attributed to geographic regions based on the ship-to location and license and collaboration services revenues attributed to geographic regions based on the location of our collaboration partners’ headquarters. Net product revenues and license revenues are recorded in accordance with ASC Topic 606, Revenue from Contracts with Customers (Topic 606). License revenues include the recognition of the portion of milestones payments allocated to the transfer of intellectual property licenses for which it had become probable in the current period that the milestone would be achieved and a significant reversal of revenues would not occur, as well as royalty revenues and our share of profits under our collaboration agreement with Genentech. Collaboration services revenues were recorded in accordance with ASU 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 and by analogy to Topic 606. Collaboration services revenues include the recognition of deferred revenues for the portion of upfront and milestone payments allocated to our research and development services performance obligations, development cost reimbursements earned under our collaboration agreements, product supply revenues, net of product supply costs, and the royalties we paid on sales of products containing cabozantinib by our collaboration partners. We received notification that, effective January 1, 2021, Royalty Pharma plc (Royalty Pharma) acquired from GlaxoSmithKline (GSK) all rights, title and interest in royalties on net product sales containing cabozantinib for non-U.S. markets for the full term of the royalty and for the U.S. market through September 2026, after which time U.S. royalties will revert back to GSK. The allowance for chargebacks, discounts for prompt payment and other are recorded as a reduction of trade receivables, net and the remaining reserves are recorded as rebates and fees due to customers in the accompanying Condensed Consolidated Balance Sheets. Contract Assets and Liabilities We receive payments from our collaboration partners based on billing schedules established in each contract. Amounts are recorded as accounts receivable when our right to consideration is unconditional. We may also recognize revenue in advance of the contractual billing schedule and such amounts are recorded as a contract asset when recognized. We may be required to defer recognition of revenue for upfront and milestone payments until we perform our obligations under these arrangements, and such amounts are recorded as deferred revenue upon receipt or when due. For those contracts that have multiple performance obligations, contract assets and liabilities are reported on a net basis at the contract level.

Revenues (Tables)

Revenues (Tables)	6 Months Ended
	Jul. 02, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Revenues consisted of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Product revenues: Gross product revenues $ 380,204 $ 229,898 $ 694,409 $ 482,464 Discounts and allowances (95,956) (51,168) (182,949) (109,854) Net product revenues 284,248 178,730 511,460 372,610 Collaboration revenues: License revenues 39,640 59,234 67,168 80,113 Collaboration services revenues 61,289 21,515 76,779 33,671 Total collaboration revenues 100,929 80,749 143,947 113,784 Total revenues $ 385,177 $ 259,479 $ 655,407 $ 486,394 Net product revenues by product were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 CABOMETYX $ 275,614 $ 173,610 $ 499,209 $ 362,826 COMETRIQ 8,634 5,120 12,251 9,784 Net product revenues $ 284,248 $ 178,730 $ 511,460 $ 372,610
Schedule of Concentration Risks	The percentage of total revenues by customer who individually accounted for 10% or more of our total revenues were as follows: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Ipsen Pharma SAS 24 % 20 % 19 % 17 % Affiliates of McKesson Corporation 14 % 11 % 14 % 13 % Affiliates of CVS Health Corporation 13 % 13 % 14 % 15 % Affiliates of AmerisourceBergen Corporation 12 % 11 % 13 % 11 % Affiliates of Optum Specialty Pharmacy 8 % 10 % 9 % 11 % Accredo Health, Incorporated 8 % 10 % 8 % 9 % Takeda Pharmaceutical Company Limited 2 % 10 % 2 % 5 % The percentage of trade receivables by customer who individually accounted for 10% or more of our trade receivables were as follows: June 30, 2021 December 31, 2020 Ipsen Pharma SAS 24 % 23 % Affiliates of McKesson Corporation 21 % 12 % Affiliates of AmerisourceBergen Corporation 19 % 11 % Affiliates of CVS Health Corporation 13 % 11 % Takeda Pharmaceutical Company Limited 4 % 10 %
Schedule of Revenues Disaggregated by Geographic Region	Revenues by geographic region were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 U.S. $ 287,190 $ 181,231 $ 517,147 $ 377,827 Europe 90,921 52,917 124,727 81,953 Japan 7,066 25,331 13,533 26,614 Total revenues $ 385,177 $ 259,479 $ 655,407 $ 486,394
Schedule of Activities and Ending Reserve Balances for Significant Categories of Discounts and Allowances	The activities and ending reserve balances for each significant category of discounts and allowances, which constitute variable consideration, were as follows (in thousands): Chargebacks, Discounts for Prompt Payment and Other Other Customer Credits/Fees and Co-pay Assistance Rebates Total Balance at December 31, 2020 $ 9,853 $ 3,279 $ 17,404 $ 30,536 Provision related to sales made in: Current period 114,489 15,392 51,355 181,236 Prior periods (40) (164) 1,917 1,713 Payments and customer credits issued (108,487) (11,637) (46,349) (166,473) Balance at June 30, 2021 $ 15,815 $ 6,870 $ 24,327 $ 47,012
Schedule of Other Assets and Other Liabilities	Contract assets and liabilities were as follows (in thousands): June 30, 2021 December 31, 2020 Contract assets Current portion (1) $ 9,749 $ — Long-term portion (1) 948 — Total contract assets $ 10,697 $ — Contract liabilities: Current portion (2) $ 6,314 $ 1,790 Long-term portion (2) 8,577 3,755 Total contract liabilities $ 14,891 $ 5,545 ____________________ (1) Presented in prepaid and other current assets and other long-term assets, respectively, on the accompanying Condensed Consolidated Balance Sheets.

Collaboration Agreements, In-_2

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities (Tables)	6 Months Ended
	Jul. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Collaborative Revenues Under Collaboration Agreement	Revenues under the collaboration agreement with Ipsen were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 License revenues $ 33,656 $ 33,597 $ 56,107 $ 51,546 Collaboration services revenues 57,265 19,320 68,620 30,407 Total $ 90,921 $ 52,917 $ 124,727 $ 81,953 Revenues under the collaboration agreement with Takeda were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 License revenues $ 2,097 $ 22,946 $ 3,398 $ 22,946 Collaboration services revenues 4,024 2,195 8,159 3,264 Total $ 6,121 $ 25,141 $ 11,557 $ 26,210 Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Profits on U.S. commercialization $ 2,160 $ 1,376 $ 3,954 $ 2,783 Royalty revenues on ex-U.S. sales $ 782 $ 1,125 $ 1,733 $ 2,434

Cash and Investments (Tables)

Cash and Investments (Tables)	6 Months Ended
	Jul. 02, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	A reconciliation of cash, cash equivalents, and restricted cash equivalents reported in the accompanying Condensed Consolidated Balance Sheets to the amount reported within the accompanying Condensed Consolidated Statements of Cash Flows was as follows (in thousands): June 30, 2021 December 31, 2020 Cash and cash equivalents $ 492,462 $ 319,217 Restricted cash equivalents included in other long-term assets 46,839 1,555 Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows $ 539,301 $ 320,772
Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	A reconciliation of cash, cash equivalents, and restricted cash equivalents reported in the accompanying Condensed Consolidated Balance Sheets to the amount reported within the accompanying Condensed Consolidated Statements of Cash Flows was as follows (in thousands): June 30, 2021 December 31, 2020 Cash and cash equivalents $ 492,462 $ 319,217 Restricted cash equivalents included in other long-term assets 46,839 1,555 Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows $ 539,301 $ 320,772
Schedule of Investments by Security Type	Cash, cash equivalents, restricted cash equivalents and investments consisted of the following (in thousands): June 30, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 716,916 $ 141 $ — $ 717,057 Corporate bonds 489,678 2,630 (166) 492,142 U.S. Treasury and government-sponsored enterprises 132,036 43 (13) 132,066 Municipal bonds 14,261 41 (4) 14,298 Total debt securities available-for-sale 1,352,891 2,855 (183) 1,355,563 Cash 88,511 — — 88,511 Money market funds 179,306 — — 179,306 Certificates of deposit 115,706 — — 115,706 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,736,414 $ 2,855 $ (183) $ 1,739,086 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 569,456 $ 372 $ — $ 569,828 Corporate bonds 543,520 5,244 (7) 548,757 U.S. Treasury and government-sponsored enterprises 208,326 232 (4) 208,554 Municipal bonds 28,680 83 (1) 28,762 Total debt securities available-for-sale 1,349,982 5,931 (12) 1,355,901 Cash 82,176 — — 82,176 Money market funds 40,761 — — 40,761 Certificates of deposit 60,004 — — 60,004 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,532,923 $ 5,931 $ (12) $ 1,538,842
Schedule of Fair Value and Gross Unrealized Losses of Investments Available-for-Sale in an Unrealized Loss Position	The fair value and gross unrealized losses on debt securities available-for-sale in an unrealized loss position were as follows (in thousands): June 30, 2021 Fair Value Gross Unrealized Losses Commercial paper $ 1,002 $ — Corporate bonds 154,767 (166) U.S. Treasury and government-sponsored enterprises 38,088 (13) Municipal bonds 5,897 (4) Total $ 199,754 $ (183) December 31, 2020 Fair Value Gross Unrealized Losses Corporate bonds $ 28,445 $ (7) U.S. Treasury and government-sponsored enterprises 21,989 (4) Municipal bonds 5,865 (1) Total $ 56,299 $ (12)
Schedule of Fair Value of Cash Equivalents and Investments by Contractual Maturity	The fair value of debt securities available-for-sale by contractual maturity was as follows (in thousands): June 30, 2021 December 31, 2020 Maturing in one year or less $ 1,015,650 $ 1,034,150 Maturing after one year through five years 339,913 321,751 Total debt securities available-for-sale $ 1,355,563 $ 1,355,901

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jul. 02, 2021
Fair Value Disclosures [Abstract]
Schedule of Classification of Financial Assets Measured and Recorded at Fair Value on a Recurring Basis	The classifications within the fair value hierarchy of our financial assets that were measured and recorded at fair value on a recurring basis were as follows (in thousands): June 30, 2021 Level 1 Level 2 Total Commercial paper $ — $ 717,057 $ 717,057 Corporate bonds — 492,142 492,142 U.S. Treasury and government-sponsored enterprises — 132,066 132,066 Municipal bonds — 14,298 14,298 Total debt securities available-for-sale — 1,355,563 1,355,563 Money market funds 179,306 — 179,306 Certificates of deposit — 115,706 115,706 Total financial assets carried at fair value $ 179,306 $ 1,471,269 $ 1,650,575 December 31, 2020 Level 1 Level 2 Total Commercial paper $ — $ 569,828 $ 569,828 Corporate bonds — 548,757 548,757 U.S. Treasury and government-sponsored enterprises — 208,554 208,554 Municipal bonds — 28,762 28,762 Total debt securities available-for-sale — 1,355,901 1,355,901 Money market funds 40,761 — 40,761 Certificates of deposit — 60,004 60,004 Total financial assets carried at fair value $ 40,761 $ 1,415,905 $ 1,456,666

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jul. 02, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): June 30, 2021 December 31, 2020 Raw materials $ 6,905 $ 7,773 Work in process 25,951 20,610 Finished goods 8,587 7,291 Total $ 41,443 $ 35,674 Balance Sheet classification: Current portion included in inventory $ 24,982 $ 20,973 Long-term portion included in other long-term assets 16,461 14,701 Total $ 41,443 $ 35,674

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jul. 02, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Allocated Employee Stock-Based Compensation Expense	We allocated the stock-based compensation expense for our equity incentive plans and our Employee Stock Purchase Plan (ESPP) as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Research and development $ 13,667 $ 6,112 $ 26,063 $ 11,198 Selling, general and administrative 14,368 10,042 36,625 18,938 Total stock-based compensation expense $ 28,035 $ 16,154 $ 62,688 $ 30,136 Stock-based compensation for each type of award under our equity incentive plans and ESPP were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Stock options $ 5,902 $ 5,301 $ 10,596 $ 10,295 Restricted stock units 15,412 8,599 27,081 16,396 Performance stock units 4,698 1,429 22,645 1,925 ESPP 2,023 825 2,366 1,520 Total stock-based compensation expense $ 28,035 $ 16,154 $ 62,688 $ 30,136
Schedule of Share-Based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions	A Monte Carlo simulation model was used to determine the grant date fair value of $24.54 for the 2021 PSUs based on the following assumptions: Fair value of the Company’s common stock on grant date $ 21.31 Expected volatility 49 % Risk-free interest rate 0.29 % Dividend yield — %

Net Income Per Share (Tables)

Net Income Per Share (Tables)	6 Months Ended
	Jul. 02, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share	Net income per share - basic and diluted, were computed as follows (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Numerator: Net income $ 96,092 $ 66,821 $ 97,693 $ 115,433 Denominator: Weighted-average common shares outstanding — basic 314,117 307,807 313,295 306,598 Dilutive securities 8,824 10,337 8,819 10,394 Weighted-average common shares outstanding — diluted 322,941 318,144 322,114 316,992 Net income per share — basic $ 0.31 $ 0.22 $ 0.31 $ 0.38 Net income per share — diluted $ 0.30 $ 0.21 $ 0.30 $ 0.36
Schedule of Potential Shares of Common Stock Not Included in the Computation of Diluted Net Income (Loss) Per Share	The weighted-average potential common shares excluded from our calculation were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Anti-dilutive securities and contingently issuable shares excluded 12,285 8,812 11,146 10,413

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Details)	6 Months Ended
	Jul. 02, 2021productsegment
Organization And Summary Of Significant Policies [Line Items]
Number of business segments | segment	1
Resulting from discovery efforts
Organization And Summary Of Significant Policies [Line Items]
Number of products that entered in the commercial marketplace	4
Products derived from other compounds
Organization And Summary Of Significant Policies [Line Items]
Number of products that entered in the commercial marketplace	2

Revenues - Revenues by Disaggre

Revenues - Revenues by Disaggregated Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 385,177	$ 259,479	$ 655,407	$ 486,394
Gross product revenues
Disaggregation of Revenue [Line Items]
Total revenues	380,204	229,898	694,409	482,464
Discounts and allowances
Disaggregation of Revenue [Line Items]
Total revenues	(95,956)	(51,168)	(182,949)	(109,854)
Net product revenues
Disaggregation of Revenue [Line Items]
Total revenues	284,248	178,730	511,460	372,610
License revenues
Disaggregation of Revenue [Line Items]
Total revenues	39,640	59,234	67,168	80,113
Collaboration services revenues
Disaggregation of Revenue [Line Items]
Total revenues	61,289	21,515	76,779	33,671
Total collaboration revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 100,929	$ 80,749	$ 143,947	$ 113,784

Revenues - Revenues Disaggregat

Revenues - Revenues Disaggregated by Significant Customer (Details) - Customer Concentration Risk	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	Jan. 01, 2021
Ipsen Pharma SAS | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	24.00%	20.00%	19.00%	17.00%
Ipsen Pharma SAS | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues			24.00%		23.00%
Affiliates of McKesson Corporation | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	14.00%	11.00%	14.00%	13.00%
Affiliates of McKesson Corporation | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues			21.00%		12.00%
Affiliates of CVS Health Corporation | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	13.00%	13.00%	14.00%	15.00%
Affiliates of CVS Health Corporation | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues			13.00%		11.00%
Affiliates of AmerisourceBergen Corporation | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	12.00%	11.00%	13.00%	11.00%
Affiliates of AmerisourceBergen Corporation | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues			19.00%		11.00%
Affiliates of Optum Specialty Pharmacy | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	8.00%	10.00%	9.00%	11.00%
Accredo Health, Incorporated | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	8.00%	10.00%	8.00%	9.00%
Takeda Pharmaceutical Company Limited | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	2.00%	10.00%	2.00%	5.00%
Takeda Pharmaceutical Company Limited | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues			4.00%		10.00%

Revenues - Revenues Disaggreg_2

Revenues - Revenues Disaggregated by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 385,177	$ 259,479	$ 655,407	$ 486,394
U.S.
Disaggregation of Revenue [Line Items]
Total revenues	287,190	181,231	517,147	377,827
Europe
Disaggregation of Revenue [Line Items]
Total revenues	90,921	52,917	124,727	81,953
Japan
Disaggregation of Revenue [Line Items]
Total revenues	$ 7,066	$ 25,331	$ 13,533	$ 26,614

Revenues - Net Product Revenues

Revenues - Net Product Revenues Disaggregated by Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Disaggregation of Revenue [Line Items]
Net product revenues	$ 385,177	$ 259,479	$ 655,407	$ 486,394
CABOMETYX
Disaggregation of Revenue [Line Items]
Net product revenues	275,614	173,610	499,209	362,826
COMETRIQ
Disaggregation of Revenue [Line Items]
Net product revenues	8,634	5,120	12,251	9,784
Net product revenues
Disaggregation of Revenue [Line Items]
Net product revenues	$ 284,248	$ 178,730	$ 511,460	$ 372,610

Revenues - Activities and Endin

Revenues - Activities and Ending Reserve Balances for Significant Categories of Discounts and Allowances (Details) $ in Thousands	6 Months Ended
	Jul. 02, 2021USD ($)
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	$ 30,536
Provision related to sales made in:
Current period	181,236
Prior periods	1,713
Payments and customer credits issued	(166,473)
Balance at June 30, 2021	47,012
Chargebacks, Discounts for Prompt Payment and Other
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	9,853
Provision related to sales made in:
Current period	114,489
Prior periods	(40)
Payments and customer credits issued	(108,487)
Balance at June 30, 2021	15,815
Other Customer Credits/Fees and Co-pay Assistance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	3,279
Provision related to sales made in:
Current period	15,392
Prior periods	(164)
Payments and customer credits issued	(11,637)
Balance at June 30, 2021	6,870
Rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	17,404
Provision related to sales made in:
Current period	51,355
Prior periods	1,917
Payments and customer credits issued	(46,349)
Balance at June 30, 2021	$ 24,327

Revenues - Contract Assets and

Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020	Jan. 01, 2021
Contract assets
Current portion	$ 9,749		$ 9,749		$ 0
Long-term portion	948		948		0
Total contract assets	10,697		10,697		0
Contract liabilities:
Current portion	6,314		6,314		1,790
Long-term portion	8,577		8,577		3,755
Total contract liabilities	14,891		14,891		$ 5,545
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Contract revenue recognized, including revenue from deferred revenue beginning balance			4,800	$ 3,400
Revenues recognized for performance obligations satisfied in previous periods	40,600	$ 62,000	67,800	$ 82,200
Remaining performance obligation	86,900		86,900
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone receivable upon achievement of development achievement	12,500		12,500
Collaborative arrangement, revenue recognized upon development milestone achievement	11,800
Remaining performance obligation	$ 46,200		$ 46,200

Collaboration Agreements, In-_3

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - Collaboration Revenues under the Collaboration Agreement with Ipsen (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 385,177	$ 259,479	$ 655,407	$ 486,394
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	90,921	52,917	124,727	81,953
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	39,640	59,234	67,168	80,113
License revenues | Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	33,656	33,597	56,107	51,546
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	61,289	21,515	76,779	33,671
Collaboration services revenues | Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 57,265	$ 19,320	$ 68,620	$ 30,407

Collaboration Agreements, In-_4

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - Ipsen Collaboration Narrative (Details) $ in Millions	Jul. 02, 2021USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 86.9
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 46.2

Collaboration Agreements, In-_5

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - Collaboration Revenues under the Collaboration Agreement with Takeda (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 385,177	$ 259,479	$ 655,407	$ 486,394
Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	6,121	25,141	11,557	26,210
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	39,640	59,234	67,168	80,113
License revenues | Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	2,097	22,946	3,398	22,946
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	61,289	21,515	76,779	33,671
Collaboration services revenues | Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 4,024	$ 2,195	$ 8,159	$ 3,264

Collaboration Agreements, In-_6

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - Takeda Collaboration Narrative (Details) $ in Millions	Jul. 02, 2021USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 86.9
Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 40.7

Collaboration Agreements, In-_7

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - GSK (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Collaboration Agreement with GlaxoSmithKline
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty expense	$ 12.1	$ 7.6	$ 22.2	$ 15.7
GSK
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percent of royalty on net sale			3.00%

Collaboration Agreements, In-_8

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - Royalty Revenues under the Collaboration Agreement with Genentech (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty revenues on ex-U.S. sales	$ 385,177	$ 259,479	$ 655,407	$ 486,394
Collaborative Arrangement with Genentech | Cotellic
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Profits on U.S. commercialization	2,160	1,376	3,954	2,783
Royalty revenues on ex-U.S. sales	$ 782	$ 1,125	$ 1,733	$ 2,434

Collaboration Agreements, In-_9

Collaboration Agreements, In-Licensing Arrangements And Business Development Activities - In-Licensing Collaborations (Details) $ in Millions	6 Months Ended
	Jul. 02, 2021USD ($)
Asset Acquisition [Line Items]
Upfront payment	$ 17
Collaborative arrangement, maximum aggregate development milestone payments	58.5
Collaborative arrangement, maximum aggregate regulatory milestone payments	139
Collaborative arrangement, maximum aggregate commercial milestone payments	377.5
Collaborative Agreement With GamaMabs Pharma SA
Asset Acquisition [Line Items]
Payments to acquire assets	5
Payment upon closing of transaction	9
Asset acquisition, maximum aggregate development milestone payments	42
Asset acquisition, maximum aggregate regulatory milestone payments	$ 22.5

Cash and Investments - Reconcil

Cash and Investments - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021	Jul. 03, 2020	Jan. 03, 2020
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 492,462	$ 319,217
Restricted cash equivalents included in other long-term assets	46,839	1,555
Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows	$ 539,301	$ 320,772	$ 528,779	$ 268,137

Cash and Investments - Narrativ

Cash and Investments - Narrative (Details)	Jul. 02, 2021USD ($)investment	Jan. 01, 2021USD ($)investment	Jul. 03, 2020USD ($)
Investments, Debt and Equity Securities [Abstract]
Restricted cash short-term investments	$ 45,300,000
Interest receivable	$ 3,300,000	$ 4,500,000
Number of investments in an unrealized loss position | investment	53	14
Allowance for credit losses	$ 0		$ 0

Cash and Investments - Investme

Cash and Investments - Investments by Security Type (Details) - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021
Debt securities available-for-sale:
Amortized Cost	$ 1,352,891	$ 1,349,982
Gross Unrealized Gains	2,855	5,931
Gross Unrealized Losses	(183)	(12)
Fair Value	1,355,563	1,355,901
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	1,736,414	1,532,923
Gross Unrealized Gains	2,855	5,931
Gross Unrealized Losses	(183)	(12)
Fair Value	1,739,086	1,538,842
Commercial paper
Debt securities available-for-sale:
Amortized Cost	716,916	569,456
Gross Unrealized Gains	141	372
Gross Unrealized Losses	0	0
Fair Value	717,057	569,828
Corporate bonds
Debt securities available-for-sale:
Amortized Cost	489,678	543,520
Gross Unrealized Gains	2,630	5,244
Gross Unrealized Losses	(166)	(7)
Fair Value	492,142	548,757
U.S. Treasury and government-sponsored enterprises
Debt securities available-for-sale:
Amortized Cost	132,036	208,326
Gross Unrealized Gains	43	232
Gross Unrealized Losses	(13)	(4)
Fair Value	132,066	208,554
Municipal bonds
Debt securities available-for-sale:
Amortized Cost	14,261	28,680
Gross Unrealized Gains	41	83
Gross Unrealized Losses	(4)	(1)
Fair Value	14,298	28,762
Cash
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	88,511	82,176
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	88,511	82,176
Money market funds
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	179,306	40,761
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	179,306	40,761
Certificates of deposit
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	115,706	60,004
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 115,706	$ 60,004

Cash and Investments - Fair Val

Cash and Investments - Fair Value and Gross Unrealized Losses of Investments Available-for-Sale in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	$ 199,754	$ 56,299
Gross Unrealized Losses	(183)	(12)
Commercial paper
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	1,002
Gross Unrealized Losses	0
Corporate bonds
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	154,767	28,445
Gross Unrealized Losses	(166)	(7)
U.S. Treasury and government-sponsored enterprises
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	38,088	21,989
Gross Unrealized Losses	(13)	(4)
Municipal bonds
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	5,897	5,865
Gross Unrealized Losses	$ (4)	$ (1)

Cash and Investments - Fair V_2

Cash and Investments - Fair Value of Cash Equivalents and Investments by Contractual Maturity (Details) - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021
Investments, Debt and Equity Securities [Abstract]
Maturing in one year or less	$ 1,015,650	$ 1,034,150
Maturing after one year through five years	339,913	321,751
Total debt securities available-for-sale	$ 1,355,563	$ 1,355,901

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Jul. 02, 2021	Jan. 01, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	$ 1,355,563	$ 1,355,901
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	1,355,563	1,355,901
Total financial assets carried at fair value	1,650,575	1,456,666
Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Total financial assets carried at fair value	179,306	40,761
Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	1,355,563	1,355,901
Total financial assets carried at fair value	1,471,269	1,415,905
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	717,057	569,828
Commercial paper | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	717,057	569,828
Commercial paper | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Commercial paper | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	717,057	569,828
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	492,142	548,757
Corporate bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	492,142	548,757
Corporate bonds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Corporate bonds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	492,142	548,757
U.S. Treasury and government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	132,066	208,554
U.S. Treasury and government-sponsored enterprises | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	132,066	208,554
U.S. Treasury and government-sponsored enterprises | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
U.S. Treasury and government-sponsored enterprises | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	132,066	208,554
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	14,298	28,762
Municipal bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	14,298	28,762
Municipal bonds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Municipal bonds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale		28,762
Money market funds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	179,306	40,761
Money market funds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	179,306	40,761
Money market funds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Certificates of deposit | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	115,706	60,004
Certificates of deposit | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Certificates of deposit | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 115,706	$ 60,004

Fair Value Measurements - Narra

Fair Value Measurements - Narratives (Details) - 6 months ended Jul. 02, 2021 - Foreign Exchange Forward € in Millions, $ in Millions	USD ($)	EUR (€)forwardContract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of contract | forwardContract		1
Derivative notional amount | €		€ 9.3
Derivative term of contract	3 months
Gain on derivative instruments, pretax | $	$ 0.3

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jan. 01, 2021
Inventory [Line Items]
Raw materials	$ 6,905		$ 7,773
Work in process	25,951		20,610
Finished goods	8,587		7,291
Total	41,443		35,674
Inventory write-down	2,300	$ 1,300
Current portion included in inventory
Inventory [Line Items]
Total	24,982		20,973
Long-term portion included in other long-term assets
Inventory [Line Items]
Total	$ 16,461		$ 14,701

Stock-Based Compensation - Allo

Stock-Based Compensation - Allocated Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 28,035	$ 16,154	$ 62,688	$ 30,136
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	13,667	6,112	26,063	11,198
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 14,368	$ 10,042	$ 36,625	$ 18,938

Stock-Based Compensation - Base

Stock-Based Compensation - Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 28,035	$ 16,154	$ 62,688	$ 30,136
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	5,902	5,301	10,596	10,295
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	15,412	8,599	27,081	16,396
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	4,698	1,429	22,645	1,925
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,023	$ 825	$ 2,366	$ 1,520

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)		8,254,455		8,254,455
Reduction in share reserve after stock option or stock appreciation award (in shares)				1
Reduction in share reserve after all other awards (in shares)				1.5
Stock-based compensation		$ 28,035	$ 16,154	$ 62,688	$ 30,136
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in the period (in shares)				1,733,554
Options granted in the period (in dollars per share)				$ 22.50
Weighted average grant-date fair value (in dollars per share)				$ 9.70
Options outstanding (in shares)		15,443,578		15,443,578
Unrecognized compensation expense		$ 32,200		$ 32,200
Stock-based compensation		5,902	5,301	10,596	10,295
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense		$ 149,000		$ 149,000
Number of awards granted (in shares)				3,575,190
Weighted average grant date fair value, awarded (in dollars per share)				$ 21.76
Number of awards outstanding (in shares)		8,314,774		8,314,774
Stock-based compensation		$ 15,412	8,599	$ 27,081	16,396
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense		$ 155,700		$ 155,700
Number of awards granted (in shares)	1,027,650
Weighted average grant date fair value, awarded (in dollars per share)				$ 24.54
Number of awards outstanding (in shares)		8,709,765		8,709,765
Maximum potential to vest	200.00%
Stock-based compensation		$ 4,698	$ 1,429	$ 22,645	$ 1,925
Performance stock units | Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting award percentage	50.00%
Performance stock units | Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year

Stock-Based Compensation - Esti

Stock-Based Compensation - Estimate Grant-Date Fair Value (Details) - Performance stock units	6 Months Ended
	Jul. 02, 2021$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, awarded (in dollars per share)	$ 24.54
Fair value of the Company's common stock on grant date (in dollars per share)	$ 21.31
Expected volatility	49.00%
Risk-free interest rate	0.29%
Dividend yield	0.00%

Provision For Income Taxes (Det

Provision For Income Taxes (Details)	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate	23.10%	17.20%	20.50%	18.00%

Net Income Per Share - Computat

Net Income Per Share - Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Numerator:
Net income	$ 96,092	$ 66,821	$ 97,693	$ 115,433
Denominator:
Weighted-average common shares outstanding - basic (in shares)	314,117	307,807	313,295	306,598
Dilutive securities (in shares)	8,824	10,337	8,819	10,394
Weighted-average common shares outstanding - diluted (in shares)	322,941	318,144	322,114	316,992
Net income per share - basic (in dollars per share)	$ 0.31	$ 0.22	$ 0.31	$ 0.38
Net income per share - diluted (in dollars per share)	$ 0.30	$ 0.21	$ 0.30	$ 0.36

Net Income Per Share - Potentia

Net Income Per Share - Potential Shares of Common Stock Not Included in the Computation of Diluted Net Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Share-based Payment Arrangement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities and contingently issuable shares excluded (in shares)	12,285	8,812	11,146	10,413