Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Acquired in-process research and development expenses Research And Development Asset Acquired In Transaction Other Than Business Combination Or Joint Venture Formation, Writeoff, Net Research And Development Asset Acquired In Transaction Other Than Business Combination Or Joint Venture Formation, Writeoff, Net Intangible asset – sofosbuvir Intangible Asset - Sofosbuvir [Member] Sofosbuvir [Member] Trading Arrangement: Trading Arrangement [Axis] Asset Acquisition [Table] Asset Acquisition [Table] Maximum Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Title of each class Title of 12(b) Security Debt Securities, Available-for-Sale [Table] Debt Securities, Available-for-Sale [Table] Carrying value Reported Value Measurement [Member] Document Fiscal Year Focus Document Fiscal Year Focus 4.60% Senior Unsecured Notes Due September 2035 4.60% Senior Unsecured Notes Due September 2035 [Member] 4.60% Senior Unsecured Notes Due September 2035 Tubulis GmbH Tubulis GmbH [Member] Tubulis GmbH Adjustment to Compensation, Amount Adjustment to Compensation Amount Fair value of term loan Lines of Credit, Fair Value Disclosure Financial Instrument [Axis] Financial Instrument [Axis] Customer [Axis] Customer [Axis] Segment Reporting [Abstract] Common stock, par value $0.001 per share; 5,600 shares authorized; 1,241 shares issued and outstanding Common Stock, Value, Issued Total Cell Therapy Cell Therapy Products, Total Cell Therapy Product Sales [Member] Cell Therapy Products, Total Cell Therapy Product Sales Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Contract assets Contract with Customer, Asset, after Allowance for Credit Loss Net unrealized gain (loss), tax Other Comprehensive Income (Loss) before Reclassifications, Tax Other 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commitments cancelled Line Of Credit Facility, Amount Cancelled Line Of Credit Facility, Amount Cancelled Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Revenue share with Janssen Ireland and royalties for licenses of intellectual property Contract with Customer, Performance Obligation Satisfied in Previous Period Work in process Inventory, Work in Process, Net of Reserves Contingent value right, sales threshold Asset Acquisition, Minimum Sales Threshold, Grant Of One Contingent Value Right Asset Acquisition, Minimum Sales Threshold, Grant Of One Contingent Value Right Total HIV HIV Product Sales [Member] HIV Product Sales Entity Address, City or Town Entity Address, City or Town Total consideration transferred Asset Acquisition, Consideration Transferred Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Basis of 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Liability - California [Member] Product Liability - California Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Less: Current portion of long-term debt, net Long-Term Debt, Current Maturities Interest income Investment Income, Nonoperating U.S. UNITED STATES Concentration Risk Type [Axis] Concentration Risk Type [Axis] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Litigation Case [Axis] Litigation Case [Axis] Foreign Currency Translation Adjustment Indefinite-Lived Intangible Assets, Foreign Currency Translation Gain (Loss), Cumulative Gain (Loss) Indefinite-Lived Intangible Assets, Foreign Currency Translation Gain (Loss), Cumulative Gain (Loss) Noncontrolling Interest Noncontrolling Interest [Member] Genvoya HIV Products, Genvoya [Member] HIV Products, Genvoya [Member] Related Party [Axis] Related and Nonrelated Parties [Axis] Other comprehensive income (loss), net Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Summary of Change in Fair Value of Contingent Consideration Liability Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Total debt, net Borrowed amount Long-Term Debt Ouro Medicines LLC Ouro Medicines LLC [Member] Ouro Medicines LLC Other Other Products, Other [Member] Other Products, Other [Member] Proceeds from debt financing, net of issuance costs Proceeds from Debt, Net of Issuance Costs Document Period End Date Document Period End Date Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] 4.80% Senior Unsecured Notes Due In November 2029 4.80% Senior 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Long-Term Debt, Gross Symtuza - Revenue share HIV Products, Symtuza - Revenue Share [Member] Products, Revenue Share-Symtuza [Member] Credit Facility [Domain] Credit Facility [Domain] Operating Activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Contingent Consideration Contingent Consideration, Liability [Member] Contingent Consideration, Liability Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Intangible Assets [Line Items] Intangible Asset, Indefinite-Lived [Line Items] Shares used in diluted (loss) earnings per share calculation (in shares) Shares used in diluted (loss) earnings per share calculation (in shares) Weighted Average Number of Shares Outstanding, Diluted Foreign Currency Translation Adjustment Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss), Cumulative Gain (Loss) Finite Lived Intangible Assets, Foreign Currency Translation Gain (Loss), Cumulative Gain 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Disease Liver Disease [Member] Liver Disease Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Net amount (legal offset) Derivative Asset, Subject to Master Netting Arrangement, after Offset and Deduction Total stockholders’ equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Discontinuances of cash flow hedges Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net Derivative [Table] Derivative [Table] Less: allowances for cash discounts and other Accounts Receivable, Cash Discounts and Other, Current Accounts Receivable, Cash Discounts and Other, Current 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Arrangement, Sales Based Tiered Royalty, Low-end, Percentage Collaborative Arrangement, Sales Based Tiered Royalty, Low-end, Percentage Accounts receivable Accounts Receivable, before Allowance for Credit Loss, Current Total costs and expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date Summary of Other (Income) Expense, Net Schedule of Other Nonoperating Income (Expense) [Table Text Block] 4.00% Senior Unsecured Notes Due September 2036 Senior Unsecured Notes Due in September 2036 [Member] Senior Unsecured Notes Due in September 2036 Interest Rate Debt Instrument, Interest Rate, Stated Percentage Counterparty Name [Domain] Counterparty Name [Domain] Total Gilead stockholders’ equity Equity, Attributable to Parent Other (income) expense, net Other (income) expense, net Nonoperating Income (Expense) Percentage share of payment of upfront cash consideration Collaborative Arrangement, Percentage Share Of Upfront Payment Collaborative Arrangement, Percentage Share Of 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Period, Tax Financing Activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Total revenues Product sales Revenue from Contract with Customer, Excluding Assessed Tax Property, plant and equipment, net Property, plant and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Accrued rebates Accrued Rebates Accrued Rebates Derivatives designated as hedges: Derivative Instruments Designated As Hedging Instruments [Abstract] Derivative Instruments Designated As Hedging Instruments Financial Instruments [Domain] Financial Instruments [Domain] Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] 4.40% Senior Unsecured Notes Due In May 2029 4.40% Senior Unsecured Notes Due In May 2029 [Member] 4.40% Senior Unsecured Notes Due In May 2029 Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] INTANGIBLE ASSETS Intangible Asset 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Trading Arrangement Termination Date Arcus Arcus Biosciences, Inc. [Member] Arcus Biosciences, Inc. 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[Member] Immunomedics, Inc. 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Notes Due October 2027 1.20% Senior Unsecured Notes Due October 2027 [Member] 1.20% Senior Unsecured Notes Due October 2027 Cash and cash equivalents Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation 4.15% Senior Unsecured Notes Due March 2047 Senior Unsecured Notes Due in March 2047 [Member] Senior Unsecured Notes Due in March 2047 [Member] 4.80% Senior Unsecured Notes Due April 2044 Senior Unsecured Notes Due in April 2044 [Member] Senior Unsecured Notes Due in April 2044 [Member] Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Accounts payable Increase (Decrease) in Accounts Payable Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Net amount (legal offset) Derivative Liability, 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Awards Granted in Covered Year that are Outstanding and Unvested [Member] General and administrative expenses General and Administrative Expense 2.80% Senior Unsecured Notes Due October 2050 2.80% Senior Unsecured Notes Due October 2050 [Member] 2.80% Senior Unsecured Notes Due October 2050 Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Total Equity Securities, FV-NI And Without Readily Determinable Fair Value And Equipment Method Investments Equity Securities, FV-NI And Without Readily Determinable Fair Value And Equipment Method Investments Preferred stock, authorized (in shares) Preferred Stock, Shares Authorized Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Preferred stock, par value $0.001 per share; 5 shares authorized; none outstanding Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Loss (gain) reclassified to net income, net of income tax expense (benefit) Reclassification 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Bluestone Income tax expense Income Tax Expense (Benefit) Intangible asset – axicabtagene ciloleucel axicabtagene ciloleucel (DLBCL) [Member] axicabtagene ciloleucel (DLBCL) [Member] Lakefront Lakefront Lakefront Biotherapeutics NV [Member] Lakefront Biotherapeutics NV Customer Concentration Risk Customer Concentration Risk [Member] Cost of goods sold Cost of Product and Service Sold Award Timing Method Award Timing Method [Text Block] Foreign currency derivative contract maturities (in months) Maturities of derivative instruments (in months) Derivative, Remaining Maturity Net change in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Effect of foreign exchange remeasurement Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Foreign Exchange Remeasurement Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Foreign Exchange Remeasurement Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Research and development expenses Research and Development Expense (Excluding Acquired in Process Cost) Net (loss) income Net (loss) income Net income (loss) Net (loss) income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Location, Statement of Financial Position, Balance [Axis] Location, Statement of Financial Position, Balance [Axis] Statement [Table] Statement [Table] Fair Value Option Investments Fair Value Option Investments [Member] Fair Value Option Investments Restatement Determination Date: Restatement Determination Date [Axis] Total Other Other Products, Total Other Product Sales [Member] Other Products, Total Other Product Sales Summary of Changes in Accumulated 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Adjustments, Footnote [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]