Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 29, 2023
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 company innovating next-generation medicines and combination regimens at the forefront of cancer care. Through the commitment of our drug discovery, development and commercialization resources, we have produced four marketed pharmaceutical products, two of which are formulations of our flagship molecule, cabozantinib. We continue to evolve our product portfolio, leveraging our investments, expertise and strategic partnerships to target an expanding range of tumor types and indications with our clinically differentiated pipeline of small molecules, antibody-drug conjugates and other biotherapeutics. Sales related to cabozantinib account for the majority of our revenues. 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 in 67 other countries as of the date of this Quarterly Report on Form 10-Q: as CABOMETYX® (cabozantinib) tablets for advanced renal cell carcinoma (both alone and in combination with Bristol-Myers Squibb Company’s OPDIVO® (nivolumab)), for previously treated hepatocellular carcinoma and for previously treated, radioactive iodine-refractory differentiated thyroid cancer; and as COMETRIQ® (cabozantinib) capsules for progressive, metastatic medullary thyroid cancer. For physicians treating these types of cancer, cabozantinib has become or is becoming an important medicine in their selection of effective therapies. 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). Basis of Presentation The accompanying unaudited 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 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 nine months ended September 30, 2023 are not necessarily indicative of the results that may be expected for the year ending December 31, 2023 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 fiscal year ended December 31, 2022, included in Part II, Item 8 of our Annual Report on Form 10-K, filed with the SEC on February 7, 2023 (Fiscal 2022 Form 10-K). We have adopted a 52- or 53-week fiscal year policy that ends on the Friday closest to December 31st. Fiscal year 2023, which is a 52-week fiscal year, will end on December 29, 2023 and fiscal year 2022, which was a 52-week fiscal year, ended on December 30, 2022. For convenience, references in this report as of and for the fiscal periods ended September 29, 2023, and as of and for the fiscal years ending December 29, 2023 and ended December 30, 2022 are indicated as being as of and for the periods ended September 30, 2023, and the years ending December 31, 2023 and ended December 31, 2022, 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 sales of products, 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 There have been no material changes to our significant accounting policies during the nine months ended September 30, 2023, as compared to the significant accounting policies disclosed in “Note 1. Organization and Summary of Significant Accounting Policies” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of our Fiscal 2022 Form 10-K. Recently Adopted Accounting Pronouncements There were no new accounting pronouncements adopted by us since our filing of the Fiscal 2022 Form 10-K, which could have a significant effect on our Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted There were no new accounting pronouncements issued since our filing of the Fiscal 2022 Form 10-K, which could have a significant effect on our Condensed Consolidated Financial Statements.