Weighted average remaining contractual term - vested and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Payroll and benefits Payroll And Benefits [Member] Payroll And Benefits Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Remaining authorized repurchase amount Share Repurchase Program, Remaining Authorized, Amount Cover [Abstract] Cover [Abstract] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Net (decrease) increase in cash, cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Acquired in-process research and development In Process Research and Development [Member] Schedule of maturities of operating lease liabilities Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Intangible Asset, Indefinite-Lived [Table] Intangible Asset, Indefinite-Lived [Table] Legal Matters Legal Costs, Policy [Policy Text Block] Trading Symbol Trading Symbol Sales Milestone Four Sales Milestone Four [Member] Sales Milestone Four Non-NEOs Non-NEOs [Member] Common stock, dividend, declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Allowance for doubtful accounts receivable, current Accounts Receivable, Allowance for Credit Loss, Current Starting share of profits outside the United States, based on sales, for collaborating party Starting share of profits outside the United States, based on sales, for collaborating party On a sliding scale, this element represents the starting share of profits outside the United States, based on sales, for the collaborating party. (Increase) decrease in accounts receivable Increase (Decrease) in Accounts Receivable Per Share Data Earnings Per Share, Policy [Policy Text Block] Inventories Inventory, Policy [Policy Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Fair Value Measurements Fair Value Disclosures [Text Block] Land Land [Member] Unrealized gain (loss) on debt securities OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Award Timing Disclosures [Line Items] January 1, 2024 Through December 31, 2026 January 1, 2024 Through December 31, 2026 [Member] January 1, 2024 Through December 31, 2026 [Member] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Sales or maturities of marketable and other securities Proceeds from Sale and Maturity of Marketable Securities Finance lease, renewal term Lessee, Finance Lease, Renewal Term Tax attribute carryforwards Deferred Tax Assets, Tax Credit Carryforwards Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] Total adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Plan Name [Domain] Plan Name [Domain] United States UNITED STATES Other noncurrent assets Other Assets, Noncurrent Leases [Abstract] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Corporate bonds Corporate Bond Securities [Member] Sales-based milestones earned Sales-Based Milestone Earned [Member] Sales-Based Milestone Earned Receivable Type [Axis] Receivable Type [Axis] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] McKesson Corporation McKesson Corporation [Member] McKesson Corporation [Member] Evkeeza Evkeeza [Member] Evkeeza Project [Domain] Project [Domain] Fixed assets and intangible assets Deferred Tax Assets, Property, Plant and Equipment Total lease assets Lease, Right-of-Use Asset Lease, Right-of-Use Asset Through December 31, 2023 Through December 31, 2023 [Member] Through December 31, 2023 [Member] Award Timing Method Award Timing Method [Text Block] Payments for Libtayo intangible asset Payments To Acquire Intangible Assets1 Payments To Acquire Intangible Assets1 Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Rebates, Chargebacks, and Discounts Rebates, Chargebacks, and Discounts [Member] A valuation allowance for rebates and chargebacks under governmental programs (including Medicaid), which are netted against revenue from product sales. Measurement Frequency [Axis] Measurement Frequency [Axis] Accrued sales-related costs Accrual For Sales-Related Costs, Current Accrual For Sales-Related Costs, Current Regeneron's share of profits Share Of Profit (Losses) [Member] Share Of Profit (Losses) Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Insider Trading Policies and Procedures [Line Items] Libtayo LIBTAYO Net Product Sales [Member] LIBTAYO Net Product Sales [Member] Use of Estimates Use of Estimates, Policy [Policy Text Block] Adjustment to Compensation, Amount Adjustment to Compensation Amount Payables and Accruals [Abstract] Payables and Accruals [Abstract] Compensation Amount Outstanding Recovery Compensation Amount Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Entity Small Business Entity Small Business Company Selected Measure Amount Company Selected Measure Amount Number of votes per share Number Of Votes Per Share Number Of Votes Per Share Tabular List, Table Tabular List [Table Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Credits/payments SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction Weighted average number of shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Other Other [Member] Other Issuance/distribution of Common Stock for 401(k) Savings Plan Stock Issued/Distributed During Period, Value, Employee Benefit Plan Stock Issued/Distributed During Period, Value, Employee Benefit Plan Imputed interest Finance Lease, Liability, Undiscounted Excess Amount Number of shareholder derivative complaints filed Number Of Shareholder Derivative Complaints Filed Number Of Shareholder Derivative Complaints Filed Credit Facility [Domain] Credit Facility [Domain] Accounts and Financing Receivables [Table] Accounts and Financing Receivables [Table] Payments in connection with Common Stock tendered for employee tax obligations Payment, Tax Withholding, Share-Based Payment Arrangement Stock repurchase program, authorized amount Share Repurchase Program, Authorized, Amount Distribution- Related Fees Distribution Related Fees [Member] A valuation allowance for distribution-related fees which are netted against revenue from product sales. Inventories Inventory Disclosure [Text Block] Stock options Share-Based Payment Arrangement, Option [Member] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] 2024 Lessee, Operating Lease, Liability, to be Paid, Year One Other Proceeds from (Payments for) Other Financing Activities Issuance/distribution of Common Stock for 401(k) Savings Plan (in shares) Stock Issued/Distributed During Period, Shares, Employee Benefit Plan Stock Issued/Distributed During Period, Shares, Employee Benefit Plan Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits Sanofi's Share of Libtayo U.S. Gross Profits [Member] Sanofi's Share of Libtayo U.S. Gross Profits Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent 2024 Finance Lease, Liability, to be Paid, Year One Marketable securities, based on contractual maturity dates Investments Classified by Contractual Maturity Date [Table Text Block] Award Type [Axis] Award Type [Axis] Work-in-process Inventory, Work in Process, Net of Reserves ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Other Other Collaboration Agreements [Member] Other Collaboration Agreements [Member] Besse Medical, a subsidiary of Cencora, Inc. Besse Medical [Member] Besse Medical [Member] Total liabilities Liabilities Schedule of cash and cash equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Exercisable (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Statements of Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Common Stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Senior unsecured revolving credit facility Revolving Credit Facility [Member] Expiration Date Trading Arrangement Expiration Date Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Operating lease liabilities - current Operating Lease, Liability, Current Total Shareholder Return Amount Total Shareholder Return Amount Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Laboratory equipment Equipment [Member] Class of treasury stock Class of Treasury Stock [Table Text Block] Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Debt Instrument [Line Items] Debt Instrument [Line Items] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Weighted-Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] (R&D expense)/Reduction of R&D expense Research and Development Expense [Member] Accumulated depreciation and amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Weighted average shares outstanding - diluted (in shares) Weighted average shares - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Sanofi Sanofi [Member] Sanofi MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Total stockholders' equity Beginning Balance Ending Balance Equity, Attributable to Parent Roche Collaboration Agreement Roche Collaboration Agreement [Member] Roche Collaboration Agreement Total deferred tax assets Deferred Tax Assets, Gross Collaboration, License, and Other Agreements Collaborative Arrangement Disclosure [Text Block] Maturities within one year Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Weighted-average remaining lease term (in years): Lease Term [Abstract] Lease Term Concentration Risk Type [Domain] Concentration Risk Type [Domain] New Accounting Pronouncements or Change in Accounting Principle [Table] Accounting Standards Update and Change in Accounting Principle [Table] Provisions SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Other Account Selling, general, and administrative Selling, General and Administrative Expense Employer contribution expense to 401(k) Savings Plan Defined Contribution Plan, Cost Net product sales Product [Member] Number of shares authorized for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Document Fiscal Period Focus Document Fiscal Period Focus All Executive Categories All Executive Categories [Member] Effect of dilutive securities (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Sales-Based Milestone One Sales-Based Milestone One [Member] Sales-Based Milestone One Finite-lived intangible asset, expected amortization, year two Finite-Lived Intangible Asset, Expected Amortization, Year Two Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Weighted average remaining contractual term (in years) - outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term ASSETS Assets: Assets [Abstract] Expected dividend yield Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Document Type Document Type Schedule of significant segment expenses Schedule of Segment Reporting Information, by Segment [Table Text Block] Purchases of marketable and other securities Payments to Acquire Marketable Securities Weighted average remaining contractual term - exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Amortized Cost Basis Debt Securities, Available-for-Sale, Amortized Cost Schedule of accounts receivable and deferred revenue information Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Maximum Maximum [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Net Carrying Amount Finite-Lived Intangible Assets, Net Furniture and fixtures Furniture and Fixtures [Member] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Royalty expense, net of reimbursements from collaborators Royalty Expense Accounts payable Accounts Payable, Current Schedule of weighted-average values of assumptions used in computing fair value of option grants Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Total lease cost Lease, Cost Audit Information [Abstract] Audit Information [Abstract] Effect of dilutive securities: Weighted Average Number of Shares Outstanding, Diluted, Adjustment [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Name Outstanding Recovery, Individual Name Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Antidilutive securities Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Furniture, office equipment, and other Furniture, Office Equipment And Other [Member] Furniture, Office Equipment And Other [Member] Accrued expenses and other current liabilities Accrued Liabilities and Other Liabilities Line of credit facility, expiration period Line of Credit Facility, Expiration Period Award Timing Predetermined Award Timing Predetermined [Flag] Number of sales-based milestones Number Of Sales-Based Milestones Number Of Sales-Based Milestones Subsequent Event Type [Domain] Subsequent Event Type [Domain] Restricted cash included in Other noncurrent assets Restricted Cash, Noncurrent Forecast Forecast [Member] Net income per share - diluted (in dollars per share) Earnings Per Share, Diluted Counterparty Name [Domain] Counterparty Name [Domain] Product Revenue Revenue from Contract with Customer [Policy Text Block] Income before income taxes, United States Income (Loss) from Continuing Operations before Income Taxes, Domestic Increase in deferred revenue Increase (Decrease) in Contract with Customer, Liability Total current tax expense Current Income Tax Expense (Benefit) Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Preferred Stock, shares issued (in shares) Preferred Stock, Shares Issued Customer [Axis] Customer [Axis] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Asset-backed securities Asset-Backed Securities [Member] Cancelled (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other Than Options, Cancelled In Period Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other Than Options, Cancelled In Period Proceeds from sale of property, plant, and equipment Proceeds from Sale of Property, Plant, and Equipment Cost of goods sold Cost Of Goods Sold [Member] Cost Of Goods Sold Income tax expense Total income tax expense (benefit) Income Tax Expense (Benefit) Other income (expense): Nonoperating Income (Expense) [Abstract] Sanofi Collaboration Agreement, Antibody Sanofi Collaboration Agreement, Antibody [Member] Sanofi Collaboration Agreement, Antibody [Member] Weighted average period for recognition of total unrecognized compensation expense (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Revenue from contract with customer Revenues Revenue from Contract with Customer, Excluding Assessed Tax Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Inventory write-downs and reserves Inventory Write-down Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Stock-based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Percent All Adjustments to Compensation All Adjustments to Compensation [Member] Accrued payroll and related costs Employee-related Liabilities, Current Increase in prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Additional paid-in capital Additional Paid in Capital Marketable securities Marketable Securities, Noncurrent Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Legal Entity [Axis] Legal Entity [Axis] Scenario [Domain] Scenario [Domain] Sales Milestones [Axis] Sales Milestones [Axis] Sales Milestones Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Entity Address, State or Province Entity Address, State or Province Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Financial Instruments [Domain] Financial Instruments [Domain] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Weighted-average grant date fair value of awards outstanding (in USD per share) Beginning balance (in dollars of shares) Ending balance (in dollars of shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Percentage of repayment of development balance out of profits Percentage Of Repayment Of Development Balance Out Of Profits Percentage of repayment of development balance out of profits under the collaboration agreement. Restatement Determination Date Restatement Determination Date Vested and expected to vest (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Intellia Therapeutics, Inc. Intellia Therapeutics, Inc. [Member] Intellia Therapeutics, Inc. Unrestricted Unrestricted [Member] Investments whose use is not restricted in whole or in part, by contractual agreements or regulatory requirements. Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Milestone Type [Domain] Milestone Type [Domain] Milestone Type [Domain] Property, Plant and Equipment [Table] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Outstanding at beginning of period (in dollars per share) Outstanding at end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Concentration Risk [Table] Concentration Risk [Table] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Outstanding at beginning of period (in shares) Outstanding at end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Net Income Per Share Earnings Per Share [Text Block] Subsequent Event Subsequent Event [Member] Expenses: Costs and Expenses [Abstract] Granted (in dollars of shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Share Repurchase Program, January 2023 Share Repurchase Program, January 2023 [Member] Share Repurchase Program, January 2023 Income Taxes Income Tax, Policy [Policy Text Block] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Restricted Restricted [Member] Restricted [Member] Inmazeb Inmazeb [Member] Inmazeb Amended & Restated Long-Term Incentive Plan 2014 Amended & Restated Long-Term Incentive Plan 2014 [Member] Amended & Restated Long-Term Incentive Plan 2014 Segments [Domain] Segments [Domain] Schedule of maturities of finance lease liabilities Finance Lease, Liability, to be Paid, Maturity [Table Text Block] Total finance lease costs Finance Lease, Cost Finance Lease, Cost Operating leases Lessee, Operating Lease, Discount Rate Unrecognized Tax Benefits [Roll Forward] Unrecognized Tax Benefits [Roll Forward] Summary of Recently Issued Accounting Standards Accounting Standards Update and Change in Accounting Principle [Table Text Block] PEO PEO [Member] Name Trading Arrangement, Individual Name Depreciation and amortization expense Depreciation, Depletion And Amortization, Excluding Intangible Assets Depreciation, Depletion And Amortization, Excluding Intangible Assets Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Entity Public Float Entity Public Float Operating leases Lessee, Operating Lease, Remaining Lease Term Treasury Stock, at cost; 28.2 shares in 2024 and 25.5 shares in 2023 Treasury Stock, Common, Value Milestone Type [Axis] Milestone Type [Axis] Milestone Type Schedules of concentration of risk, by risk factor Schedules of Concentration of Risk, by Risk Factor [Table Text Block] Two Individual Customers Two Individual Customers [Member] Two Individual Customers Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Revenue, remaining performance obligation, variable consideration amount Revenue, Remaining Performance Obligation, Variable Consideration Amount Revenue, Remaining Performance Obligation, Variable Consideration Amount Cost of collaboration and contract manufacturing Collaboration and Contract Manufacturing [Member] Collaboration and Contract Manufacturing [Member] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Expected payment, unrecognized tax benefits Decrease in Unrecognized Tax Benefits is Reasonably Possible Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount One time payment Payment To Collaborating Party Payment To Collaborating Party Local Phone Number Local Phone Number Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] PEO Total Compensation Amount PEO Total Compensation Amount Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Statement of Income Location, Balance [Axis] Statement of Income Location, Balance [Axis] Vested and expected to vest (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Computer equipment and software Computer Equipment And Software [Member] Computer Equipment And Software [Member] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Common Stock Common Stock [Member] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Line of credit Line of Credit [Member] Direct research and development expenses(a) Direct Expense [Member] Direct Expense Accrued clinical expenses Accrued Clinical Trial Expense Current Carrying value as of the balance sheet date of obligations incurred (and for which invoices have not been received) in connection with clinical trials. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Intangible Assets Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares) Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Entity Central Index Key Entity Central Index Key Scenario [Axis] Scenario [Axis] Percentage of quarterly profits require to be paid for reimbursement of development costs Percentage Of Quarterly Profits Required To Be Paid For Reimbursement Of Development Costs Percentage Of Quarterly Profits Required To Be Paid For Reimbursement Of Development Costs Schedule of inventory Schedule of Inventory, Current [Table Text Block] Accrued Expenses and Other Current Liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Stockholders' Equity Equity [Text Block] Increase (decrease) in accounts payable, accrued expenses, and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Financial Instrument [Axis] Financial Instrument [Axis] Stock-based compensation charges APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Restricted stock awards and restricted stock units Restricted Stock [Member] Title Trading Arrangement, Individual Title Total lease liability Total lease liabilities Lease, Liability Lease, Liability Schedule of income before income tax Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Balance as of January 1 Balance as of December 31 Unrecognized Tax Benefits City Area Code City Area Code Current liabilities: Liabilities, Current [Abstract] Auditor Location Auditor Location Accrued expenses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Weighted-average discount rate: Lease Discount Rate [Abstract] Lease Discount Rate Contingent consideration Business Combination, Contingent Consideration, Liability Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Sales-Based Milestone Two Sales-Based Milestone Two [Member] Sales-Based Milestone Two Repurchases of Common Stock Payments for Repurchase of Common Stock '631 Patent '631 Patent [Member] '631 Patent Document Information [Line Items] Document Information [Line Items] Long-term debt Long-Term Debt, Excluding Current Maturities SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Weighted-Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Equity [Abstract] Equity [Abstract] Raw materials Inventory, Raw Materials, Net of Reserves Sales Milestone Five Sales Milestone Five [Member] Sales Milestone Five Retained earnings Retained Earnings (Accumulated Deficit) Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Reimbursement of research and development expenses by collaborators Research And Development Expense, Reimbursements Research And Development Expense, Reimbursements Class of Stock [Domain] Class of Stock [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Increase in inventories Increase (Decrease) in Inventories Summary of issued senior unsecured notes Schedule of Debt [Table Text Block] Net unrealized gains (losses) Equity Securities, FV-NI, Unrealized Gain (Loss) 2025 Lease, Liability, to be Paid, Year Two Lease, Liability, to be Paid, Year Two Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] Total lease liabilities Operating Lease, Liability Underlying Securities Award Underlying Securities Amount Performance-based stock options Performance Shares [Member] Marketable Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses Regeneron's Obligation Of Research And Development Expenses, Net of Reimbursement Of Research And Development Expenses [Member] Regeneron's Obligation Of Research And Development Expenses, Net of Reimbursement Of Research And Development Expenses Deferred costs Other Inventory, Net of Reserves 2028 Finance Lease, Liability, to be Paid, Year Five Amendment Flag Amendment Flag Starting share of profits outside the United States, based on sales, for company Starting share of profits outside the United States, based on sales, for Company On a sliding scale, this element represents the starting share of profits outside the United States, based on sales, for the Company. Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Schedule of restrictions on cash and cash equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] ELYEA HD ELYEA HD [Member] ELYEA HD Amortization of finance lease right-of-use assets Finance Lease, Right-of-Use Asset, Amortization Statement of Cash Flows Cash Flow, Supplemental Disclosures [Text Block] Debt Debt Disclosure [Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Reimbursement for manufacturing of commercial supplies Reimbursement for manufacturing of ex-U.S. commercial supplies Reimbursement For Manufacturing Of Commercial Supplies [Member] Reimbursement For Manufacturing Of Commercial Supplies [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Percentage of share of profits used to reimburse collaborating party for trial costs Percentage of Share of Profits Used to Reimburse Collaborating Party for Trial Costs Percentage of Share of Profits Used to Reimburse Collaborating Party for Trial Costs Entity Address, Postal Zip Code Entity Address, Postal Zip Code Ending share of profits outside the United States, based on sales, for collaborating party Ending share of profits outside the United States, based on sales, for collaborating party On a sliding scale, this element represents the ending share of profits outside the United States, based on sales, for the collaborating party. Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Certificates of deposit Certificates of Deposit [Member] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Classification of Investment [Domain] Classification of Investment [Domain] Provides general categories of investments for which information is required or determined to be disclosed. Praluent Praluent Net Product Sales [Member] Praluent Net Product Sales Auditor Name Auditor Name Ending share of profits outside the United States, based on sales, for company Ending share of profits outside the United States, based on sales, for Company On a sliding scale, this element represents the ending share of profits outside the United States, based on sales, for the Company. Forfeited (in dollars of shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Estimated useful life (in years) Property, Plant and Equipment, Useful Life Number of Shares (In millions) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Property, plant, and equipment, net Property, plant, and equipment, net Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Bayer Bayer Collaboration Agreement [Member] Bayer Collaboration Agreement [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Fair value and unrealized losses of marketable securities Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Stock, Class of Stock [Table] Stock, Class of Stock [Table] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Total assets Assets Cost of goods sold and of collaboration and contract manufacturing Cost of Goods and Services Sold Regulatory Milestone Regulatory Milestone [Member] Regulatory Milestone Cash and Cash Equivalents [Abstract] Other noncurrent liabilities Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Commitments and contingencies Commitments and Contingencies Stock-based Compensation Share-Based Payment Arrangement [Policy Text Block] Schedule of effective income tax rate reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Termination Date Trading Arrangement Termination Date Schedule of amounts recognized in the condensed consolidated balance sheet Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee [Table Text Block] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] 2025 Lessee, Operating Lease, Liability, to be Paid, Year Two Research And Development Expense, Type [Domain] Research And Development Expense, Type [Domain] Research And Development Expense, Type [Domain] Maturities after one year through five years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Debt Instrument [Axis] Debt Instrument [Axis] Reportable Segment Reportable Segment [Member] Reportable Segment Net income Net income Net income - basic and diluted Net Income (Loss) Attributable to Parent Other operating expense (income), net Other Operating Income (Expense), Net Trading Arrangement: Trading Arrangement [Axis] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Entity File Number Entity File Number Statements of Operations Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Federal Current Federal Tax Expense (Benefit) Effect of exchange rate changes on cash, cash equivalents, and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Name Forgone Recovery, Individual Name Intrinsic value - exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Deferred income taxes Increase (Decrease) in Deferred Income Taxes Other non-cash items, net Other Noncash Income (Expense) Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Gross decreases related to prior year tax positions Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount 2028 Lease, Liability, to be Paid, Year Five Lease, Liability, to be Paid, Year Five PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Adjustment to Compensation: Adjustment to Compensation [Axis] Accounts receivable Accounts Receivable [Member] Other permanent differences Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Weighted average shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Unrealized Loss - 12 Months or Greater Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Document Information [Table] Document Information [Table] Nature of Expense [Axis] Nature of Expense [Axis] Name Awards Close in Time to MNPI Disclosures, Individual Name Construction in progress Construction in Progress [Member] Contract with Customer, Duration [Axis] Contract with Customer, Duration [Axis] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Unrealized Loss - Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Entity Filer Category Entity Filer Category Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses Reimbursement Of Research And Development Expenses, Net Of Obligation For Share Of R&D Expenses [Member] Reimbursement Of Research And Development Expenses, Net Of Obligation For Share Of R&D Expenses Loss Contingencies [Line Items] Loss Contingencies [Line Items] Statistical Measurement [Domain] Statistical Measurement [Domain] Occupancy and other operating costs Occupancy And Other Operating Costs [Member] Occupancy And Other Operating Costs Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Schedule of lease cost and other information Lease, Cost [Table Text Block] ELYEA HD And EYLEA ELYEA HD And EYLEA [Member] ELYEA HD And EYLEA Share Repurchase Program, November 2021 Share Repurchase Program, November 2021 [Member] Share Repurchase Program, November 2021 Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Number of IPR filed Number of Inter Parties Review (IPR) Petitions Filed Number of Inter Parties Review (IPR) Petitions Filed Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Finance leases Lessee, Finance Lease, Discount Rate All Trading Arrangements All Trading Arrangements [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Line of credit facility, increase limit Line Of Credit Facility, Increase Limit Line Of Credit Facility, Increase Limit Basic and diluted net income (loss) per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Award vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] Cash paid for income taxes Income Taxes Paid, Net Class A Stock Common Class A [Member] Share Repurchase Program, April 2024 Share Repurchase Program, April 2024 [Member] Share Repurchase Program, April 2024 Pay vs Performance Disclosure [Line Items] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Sonoma Biotherapeutics, Inc. Sonoma Biotherapeutics, Inc. [Member] Sonoma Biotherapeutics, Inc. Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Other Performance Measure, Amount Other Performance Measure, Amount Finite-lived intangible asset, expected amortization, year three Finite-Lived Intangible Asset, Expected Amortization, Year Three Legal Matters Legal Matters and Contingencies [Text Block] Leases Lessee, Operating Leases [Text Block] Common Stock, shares outstanding (in shares) Beginning Balance (in shares) Ending Balance (in shares) Common Stock, Shares, Outstanding Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Operating lease costs Operating Lease, Cost Number of shares available for future grants (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Operating lease liabilities - noncurrent Operating Lease, Liability, Noncurrent Percentage of royalties to be paid Payments For Royalties, Percentage Payments For Royalties, Percentage Other revenue Product and Service, Other [Member] Interest on finance lease liabilities Finance Lease, Interest Expense Deferred revenue Contract with Customer, Liability, Current Entity Tax Identification Number Entity Tax Identification Number Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Gross increases related to prior year tax positions Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Number of shares (in shares) Treasury Stock, Shares, Acquired Foreign Deferred Foreign Income Tax Expense (Benefit) Reduction of SG&A expense Selling, General and Administrative Expenses [Member] Treasury Stock Treasury Stock, Common [Member] Income tax-related costs Taxes Payable, Current Maturities after five years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Plan Name [Axis] Plan Name [Axis] Thereafter Finance Lease, Liability, to be Paid, after Year Five Equity Components [Axis] Equity Components [Axis] Total undiscounted lease payments Finance Lease, Liability, to be Paid Research and Development Expenses Research and Development Expense, Policy [Policy Text Block] Fair Value Total Available-for-sale debt securities Debt Securities, Available-for-Sale Accounts Receivable Accounts Receivable [Policy Text Block] Total expenses Costs and Expenses Receivable [Domain] Receivable [Domain] Intrinsic value - outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Geographical [Axis] Geographical [Axis] Royalty rate minimum Royalty rate minimum The minimum royalty rate to be paid to the Company under the agreements. Net deferred tax assets Deferred Tax Assets, Net EYLEA EYLEA Net Product Sales [Member] Revenue during the period derived from a specified product line (EYLEA), after deducting applicable provisions for discounts, returns, rebates, chargebacks, distribution fees, and other sales-related deductions. 2028 Lessee, Operating Lease, Liability, to be Paid, Year Five Share Repurchase Program, February 2025 Share Repurchase Program, February 2025 [Member] Share Repurchase Program, February 2025 Repurchases of Common Stock Stock Repurchased During Period, Value 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] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Fair Value - Total Debt Securities, Available-for-Sale, Unrealized Loss Position Cash, cash equivalents, and restricted cash at beginning of period Cash, cash equivalents, and restricted cash at end of period Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Accrued contingent consideration in connection with acquisitions Acquisitions, Contingent Consideration Accrued But Not Yet Paid Asset Acquisitions and Business Combination, Contingent Consideration Accrued But Not Yet Paid Unrecognized stock-based compensation cost, net of estimated forfeitures Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Foreign Current Foreign Tax Expense (Benefit) Current assets: Assets, Current [Abstract] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Treasury stock (in shares) Beginning Balance, treasury (in shares) Beginning Ending, treasury (in shares) Treasury Stock, Common, Shares Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Imputed interest Lease, Liability, Undiscounted Excess Amount Lease, Liability, Undiscounted Excess Amount Product and Service [Domain] Product and Service [Domain] Vested (in dollars of shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Marketable securities Marketable Securities, Current Percentage of trial costs required to be funded by collaborating party Percentage of Trial Costs Required To Be Funded By Collaborating Party Percentage of Trial Costs Required To Be Funded By Collaborating Party Preferred Stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Security Exchange Name Security Exchange Name Classification of Investment [Axis] Classification of Investment [Axis] This element represents the general categories of investments, which may be classified as Unrestricted or Restricted. Exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Number of Shares/Units (In millions) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] State Current State and Local Tax Expense (Benefit) Contingent reimbursement obligation Contingent Reimbursement Obligation The Company's total contingent reimbursement obligation to its collaboration partner for development expenses previously funded by its collaboration partner. Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Available-for-sale debt securities Debt Securities, Available-for-Sale [Table Text Block] Research and development Total research and development expenses Research and Development Expense Goodwill and Intangible Assets Disclosure [Abstract] Common Stock, shares issued (in shares) Common Stock, Shares, Issued Entity [Domain] Entity [Domain] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Concentration risk, percentage Concentration Risk, Percentage Unrealized Loss - Total Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Common Stock, shares authorized (in shares) Common Stock, Shares Authorized Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Summary of non-cash investing and financing activities Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Entity Voluntary Filers Entity Voluntary Filers Operating Leases Operating Lease, Liability [Abstract] Indirect research and development expenses: Indirect Expense [Member] Indirect Expense Interest expense Interest Expense, Nonoperating Total deferred tax benefit Deferred Income Tax Expense (Benefit) Property, Plant, and Equipment Property, Plant and Equipment Disclosure [Text Block] Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Measured on a recurring basis Fair Value, Recurring [Member] Lab supplies and other research and development costs Lab Supplies And Other Research And Development Costs [Member] Lab Supplies And Other Research And Development Costs Accounts receivable, net Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Amounts recognized in connection with up-front payments received Amounts Recognized In Connection With Up-Front Payments [Member] Amounts Recognized In Connection With Up-Front Payments [Member] Fair Value - 12 Months or Greater Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Long-term debt Long-Term Debt Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Restricted cash included in Other current assets Restricted Cash, Current Finance leases Lessee, Finance Lease, Remaining Lease Term Reimbursement of R&D expenses Reimbursement Of Research And Development Expenses [Member] Reimbursement Of Research And Development Expenses [Member] Commercial paper Commercial Paper [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Document Annual Report Document Annual Report 2026 Finance Lease, Liability, to be Paid, Year Three Vested (in shares) Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Reimbursement of commercialization-related expenses Reimbursement Of Commercialization-Related Expenses [Member] Reimbursement Of Commercialization-Related Expenses [Member] Risk-free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Schedule of weighted-average exercise prices and weighted-average grant-date fair values of options issued Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block] Indefinite-lived intangible assets Indefinite-Lived Intangible Assets (Excluding Goodwill) Amortization expense on intangible assets Amortization of Intangible Assets Deferred revenue Contract with Customer, Liability Project [Axis] Project [Axis] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Rest Of World Outside United States Non-US [Member] 2027 Lease, Liability, to be Paid, Year Four Lease, Liability, to be Paid, Year Four Liabilities: Liabilities [Abstract] Other Sales- Related Deductions Other Sales Related Deductions [Member] A valuation allowance for other sales-related deductions which are netted against revenue from product sales. Accounting Policies [Abstract] Accounting Policies [Abstract] Revenues: Revenues [Abstract] Leasehold improvements Leasehold Improvements [Member] Current Fiscal Year End Date Current Fiscal Year End Date Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Beginning Balance Ending Balance SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Levels of twelve month sales at which sales milestone payments would be received Levels of twelve month sales at which sales milestone payments would be received Aggregate amount of twelve month sales upon which sales milestone would be received. PEO Name PEO Name Accumulated amortization of right-of-use assets Finance Lease, Right-of-Use Asset, Accumulated Amortization Award Type [Domain] Award Type [Domain] Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Deferred tax assets Deferred Income Tax Assets, Net Non-PEO NEO Non-PEO NEO [Member] Estimated Useful Life (in years) Finite-Lived Intangible Asset, Useful Life (R&D expense)/Reduction of R&D expense Research And Development Expenses And Reduction of Research And Development Expense [Member] Research And Development Expenses And Reduction of Research And Development Expense Additional Paid-in Capital Additional Paid-in Capital [Member] Finance lease liabilities Finance Lease, Liability, Noncurrent Employee Savings Plans Retirement Benefits [Text Block] Class of Stock [Line Items] Class of Stock [Line Items] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Class of Stock [Axis] Class of Stock [Axis] Interim Period, Costs Not Allocable [Domain] Interim Period, Costs Not Allocable [Domain] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] 2027 Finance Lease, Liability, to be Paid, Year Four Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Name Measure Name Entity Interactive Data Current Entity Interactive Data Current Deferred tax assets: Components of Deferred Tax Assets [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Foreign-derived intangible income deduction Effective Income Tax Rate Reconciliation, FDII, Percent Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Interest rate Debt Instrument, Interest Rate, Stated Percentage Supplemental disclosure of cash flow information Supplemental Cash Flow Information [Abstract] Equity investments Equity Securities, FV-NI Total other income (expense) Nonoperating Income (Expense) Laboratory and Office Facilities Laboratory And Office Facilities [Member] Laboratory And Office Facilities Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Auditor Firm ID Auditor Firm ID Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Income from operations Operating Income (Loss) Kathryn Guarini, Ph.D. [Member] Kathryn Guarini, Ph.D. Number of business segments Number of Reportable Segments Total liabilities and stockholders' equity Liabilities and Equity Sales related deductions activity Schedule of Sales Related Deductions Activity [Table Text Block] Tabular disclosure of the activity of sales-related deductions during the period, which includes rebates, chargebacks, discounts, and distributor-related fees. Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Debt and Equity Securities Marketable Securities, Policy [Policy Text Block] Schedule of assets measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] 2025 Finance Lease, Liability, to be Paid, Year Two Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Schedule of activity related to restricted stock awards Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Right-of-use assets obtained in exchange for operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Underlying Security Market Price Change Underlying Security Market Price Change, Percent Acquired in-process research and development in connection with asset acquisition Acquired In-Process Research And Development, Asset Acquisition Acquired In-Process Research And Development, Asset Acquisition Individual: Individual [Axis] Building and improvements Building and Building Improvements [Member] Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Forfeited (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Expected lives from grant date Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Inventories Total Inventories Inventory, Net Product and Service [Axis] Product and Service [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Statement [Line Items] Statement [Line Items] Schedule of estimated useful lives of property, plant, and equipment Schedule of property, plant and equipment Property, Plant and Equipment [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Minimum Minimum [Member] Adoption Date Trading Arrangement Adoption Date Deferred revenue Contract with Customer, Liability, Noncurrent 2029 Lease, Liability, to be Paid, after Year Five Lease, Liability, to be Paid, after Year Five Operating lease, right-of-use asset, accumulated amortization Operating Lease, Right-of-Use Asset, Accumulated Amortization Operating Lease, Right-of-Use Asset, Accumulated Amortization Other operating income Other Operating Income (Expense) [Member] Provision for doubtful accounts Accounts Receivable, Credit Loss Expense (Reversal) Segments [Axis] Segments [Axis] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] U.S. federal statutory tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Exercise Price Award Exercise Price Schedule of deferred tax assets and liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Arrangement Duration Trading Arrangement Duration Trade Accounts Receivable Trade Accounts Receivable [Member] Leases Lessee, Finance Leases [Text Block] Stockholders' equity: Equity, Attributable to Parent [Abstract] Fair Value - Less than 12 Months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Alnylam Pharmaceuticals, Inc Alnylam Pharmaceuticals, Inc [Member] Alnylam Pharmaceuticals, Inc Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Finance lease, liability Total lease liabilities Finance Lease, Liability Finite-lived intangible asset, expected amortization, year four Finite-Lived Intangible Asset, Expected Amortization, Year Four All Individuals All Individuals [Member] 2026 Lease, Liability, to be Paid, Year Three Lease, Liability, to be Paid, Year Three Contract with Customer, Duration [Domain] Contract with Customer, Duration [Domain] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Other income (expense), net Other Nonoperating Income (Expense) Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Intangible assets, net Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Assets: Assets, Fair Value Disclosure [Abstract] Clinical manufacturing costs Clinical And Manufacturing Costs [Member] Clinical And Manufacturing Costs Accrued expenses and other current liabilities Accounts Payable and Accrued Liabilities, Current Expected volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Repurchases of Common Stock (in shares) Stock Repurchased During Period, Shares Taxation of non-U.S. operations Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent One-time payment in connection with change in Japan arrangement One-time Payment in Connection With Change in Japan Arrangement [Member] One-time Payment in Connection With Change in Japan Arrangement Gross Product Revenue Gross Product Revenue [Member] Gross Product Revenue Federal Deferred Federal Income Tax Expense (Benefit) Share Repurchase Program [Domain] Share Repurchase Program [Domain] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Measure: Measure [Axis] Issuance of Common Stock for equity awards granted under long-term incentive plans Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Gross increases related to current year tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Preferred Stock, shares authorized (in shares) Preferred Stock, Shares Authorized Granted (in shares) Number of Options Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Net of Forfeitures Entity Emerging Growth Company Entity Emerging Growth Company Indefinite-Lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Schedule of accrued expenses and other current liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Finance lease right-of-use assets Finance Lease, Right-of-Use Asset, after Accumulated Amortization Sovereign bonds Sovereign Debt Securities [Member] Equity Component [Domain] Equity Component [Domain] Preferred Stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Class of Treasury Stock [Table] Class of Treasury Stock [Table] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Entity Shell Company Entity Shell Company Capitalized research and development expenses Deferred Tax Assets, Capitalized Research and Development Expenses Deferred Tax Assets, Capitalized Research and Development Expenses Sales-Based Milestones Sales-Based Milestones [Member] Sales-Based Milestones Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Royalty payment to collaborating party, percentage of net product sales Royalty Payment to Collaborating Party, Percentage of Net Product Sales Royalty Payment to Collaborating Party, Percentage of Net Product Sales Period for achieving sales target for milestone payment, rolling basis Period for Achieving Sales Target for Milestone Payment, Rolling Basis Period for Achieving Sales Target for Milestone Payment, Rolling Basis Share Repurchase Programs Share Repurchase Programs [Member] Share Repurchase Programs SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Statement [Table] Statement [Table] Interest expense Interest Expense, Debt Measurement Frequency [Domain] Measurement Frequency [Domain] Counterparty Name [Axis] Counterparty Name [Axis] Business Overview and Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Cash paid for interest (net of amounts capitalized) Interest Paid, Excluding Capitalized Interest, Operating Activities Property, plant, and equipment, gross Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Third Milestone Sales Milestone Three [Member] Sales Milestone Three Capital expenditures Payments to Acquire Productive Assets Level 1 Fair Value, Inputs, Level 1 [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Senior unsecured notes Senior Notes [Member] Exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Interest expense related to unrecognized tax benefits Unrecognized Tax Benefits, Interest on Income Taxes Expense Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Weighted-Average Fair Value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Securities owned not readily marketable Equity Securities without Readily Determinable Fair Value, Amount Acquired product rights - Libtayo Product Rights [Member] Product Rights Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Other intangibles Other Intangible Assets [Member] Income Taxes Income Tax Disclosure [Text Block] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Four 2.800% Senior Notes due September 2050 Senior Unsecured Notes Due 2050 [Member] Senior Unsecured Notes Due 2050 Interest income Interest Income, Debt Securities, Operating Checkmate Pharmaceuticals, Inc. Checkmate Pharmaceuticals, Inc. [Member] Checkmate Pharmaceuticals, Inc. Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Up-front payment to collaborating party Up-Front Payment to Collaborating Party Up-Front Payment to Collaborating Party Credit Facility [Axis] Credit Facility [Axis] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Long-term debt, fair value Long-Term Debt, Fair Value Entity Registrant Name Entity Registrant Name 2024 Lease, Liability, to be Paid, Year One Lease, Liability, to be Paid, Year One Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Depreciation and amortization Depreciation, Depletion and Amortization Maximum term of awards Share Based Compensation Arrangement By Share Based Payment Award Expiration The term (in years) when the equity-based award expires as specified in the award agreement. Intangible Assets Intangible Assets Disclosure [Text Block] Loss on foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent State Deferred State and Local Income Tax Expense (Benefit) Fair Value as of Grant Date Award Grant Date Fair Value Customer concentration risk Customer Concentration Risk [Member] Total undiscounted lease payments Lease, Liability, Payments, Due Lease, Liability, Payments, Due Intrinsic value - vested and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Level 2 Fair Value, Inputs, Level 2 [Member] Geographical [Domain] Geographical [Domain] Schedule of product sales Schedule of collaboration revenue Disaggregation of Revenue [Table Text Block] Restatement Determination Date: Restatement Determination Date [Axis] Title of 12(b) Security Title of 12(b) Security Concentration Risk Type [Axis] Concentration Risk Type [Axis] Common stock Common Stock, Value, Issued Document Financial Statement Error Correction Document Financial Statement Error Correction [Flag] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] (Gains) losses on marketable and other securities, net Marketable and Other Securities, Gain (Loss) Marketable and Other Securities, Gain (Loss) Gross decreases due to settlements and lapse of statutes of limitations Unrecognized Tax Benefits, Decrease Resulting From Settlements With Taxing Authorities And Reduction Resulting From Lapse Of Applicable Statute Of Limitations Unrecognized Tax Benefits, Decrease Resulting From Settlements With Taxing Authorities And Reduction Resulting From Lapse Of Applicable Statute Of Limitations 1.750% Senior Notes due September 2030 Senior Unsecured Notes Due 2030 [Member] Senior Unsecured Notes Due 2030 Collaboration revenue Collaboration revenue Collaboration Revenue [Member] Collaboration Revenue Equity securities Equity Securities, FV-NI, Noncurrent Unrealized gains on investments Deferred Tax Liabilities, Unrealized Gains on Trading Securities Other Deferred Tax Assets, Other Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Indefinite-Lived Intangible Assets [Line Items] Indefinite-Lived Intangible Assets [Line Items] Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Concentration Risk [Line Items] Concentration Risk [Line Items] Preferred Stock, par value $.01 per share; 30.0 shares authorized; shares issued and outstanding - none Preferred Stock, Value, Issued Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Net income per share - basic (in dollars per share) Earnings Per Share, Basic Proceeds from issuance of Common Stock Proceeds from Issuance of Common Stock Cash paid for amounts included in the measurement of operating lease liabilities (included within cash flows from operating activities) Operating Lease, Payments Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Agreements with Royalty Provisions Royalty Agreement Terms [Member] Accrued capital expenditures Capital Expenditures Incurred but Not yet Paid Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Sales Milestones [Domain] Sales Milestones [Domain] Sales Milestones Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Research And Development Expense, Type [Axis] Research And Development Expense, Type [Axis] Research And Development Expense, Type Finite-Lived Intangible Assets, Net [Abstract] Finite-Lived Intangible Assets, Net [Abstract] Total current liabilities Liabilities, Current Share Repurchase Program [Axis] Share Repurchase Program [Axis] Summary of presentation in statement of operations of payments to and from collaborators Collaborative Arrangement and Arrangement Other than Collaborative [Table Text Block] Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Finite-lived intangible asset, expected amortization, year one Finite-Lived Intangible Asset, Expected Amortization, Year One Borrowings outstanding Long-Term Line of Credit Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period U.S. government and government agency obligations US Treasury and Government [Member] Total Lease Liability Payment Due Abstract [Abstract] Lease Liability Payment Due Abstract Acquisitions Business Combinations Policy [Policy Text Block] Long-Term Incentive Plans Share-Based Payment Arrangement [Text Block] Entity Address, City or Town Entity Address, City or Town Leases Lessee, Leases [Policy Text Block] Schedule of transactions involving stock option awards Share-Based Payment Arrangement, Option, Activity [Table Text Block] Total intrinsic value - of stock options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Non-cash stock-based compensation expense Share-Based Payment Arrangement, Expense Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Granted (in dollars per share) Weighted-Average Exercise Price (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Loss Contingencies [Table] Loss Contingencies [Table] Awards forfeited (in shares) Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Schedule of intangible assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Royalty rate maximum Royalty rate maximum The maximum royalty rate to be paid to the Company under the agreements. Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Finance Leases Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Liabilities: Liabilities, Fair Value Disclosure [Abstract] Product Sales Revenue from Contract with Customer [Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Cost of stock repurchased Total cost of shares Treasury Stock, Value, Acquired, Cost Method Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Other accrued expenses and liabilities Other Accrued Liabilities, Current Total assets Assets, Fair Value Disclosure Income before income taxes, Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Non-performance based stock options Non-Performance Based Stock Options [Member] A stock option whose vesting is not contingent upon performance achievements. Finite-lived intangible asset, expected amortization, year five Finite-Lived Intangible Asset, Expected Amortization, Year Five Document Period End Date Document Period End Date Finished goods Inventory, Finished Goods, Net of Reserves Write-down in other income (expense) Equity Securities without Readily Determinable Fair Value, Impairment Loss, Annual Amount Total undiscounted lease payments Lessee, Operating Lease, Liability, to be Paid Awards outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Insider Trading Arrangements [Line Items] 2026 Lessee, Operating Lease, Liability, to be Paid, Year Three Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Document Transition Report Document Transition Report Schedule of unrecognized tax benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Income tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Percent Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Customer [Domain] Customer [Domain] Entity Current Reporting Status Entity Current Reporting Status Sanofi Collaboration Agreement, Immuno-oncology Sanofi Collaboration Agreement, Immuno-oncology [Member] Sanofi Collaboration Agreement, Immuno-oncology [Member] Retained Earnings Retained Earnings [Member] Acquired in-process research and development Acquired In-Process Research and Development Acquired In-Process Research and Development Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Schedule of components of income tax expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Statement of Income Location, Balance [Domain] Statement of Income Location, Balance [Domain] Letters of credit Letter of Credit [Member] Unrealized gain on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Company Selected Measure Name Company Selected Measure Name