Commitments and Contingencies Disclosure [Abstract] Research Collaboration and Licensing Arrangements [Table] Research Collaboration and Licensing Arrangements [Table] -- None. No documentation exists for this element. -- Research Collaboration and Licensing Agreements [Axis] Research Collaboration and Licensing Agreements [Axis] The research collaboration and licensing agreements entered into. Research Collaboration and Licensing Agreements [Domain] Research Collaboration and Licensing Agreements [Domain] Research collaboration and licensing agreements, by name. Agreements with Royalty Provisions Royalty Agreement Terms [Member] License agreement with Genentech - EYLEA License agreement with Genentech - EYLEA [Member] License agreement with Genentech - EYLEA Research Collaboration and Licensing Arrangements [Line Items] Research Collaboration and Licensing Arrangements [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Royalty rate minimum Royalty rate minimum The minimum royalty rate to be paid to the Company under the agreements. Royalty rate maximum Royalty rate maximum The maximum royalty rate to be paid to the Company under the agreements. First payment made or maybe made upon reaching minimum sales target First payment made or maybe made upon reaching minimum sales target The amount of first payment either already made by the Company or may be made by the Company upon cumulative sales reaching a minimum sales target, under the terms of the non-exclusive license agreement. Cumulative relevant sales minimum sales target Cumulative relevant sales minimum sales target Cumulative relevant sales minimum sales target Cumulative sales range, 1st tier minimum Sales range minimum 1st tier Sales range minimum 1st tier Sales range maximum 1st tier Cumulative sales range, 1st tier maximum Cumulative sales range, 1st tier maximum Cumulative sales range, 2nd tier minimum Cumulative sales range 2nd tier The 2nd tier minimum cumulative sales which would require the Company to make royalty payments. Royalty payment percentage of cumulative sales within cumulative sales range Royalty payment percentage of cumulative sale 1st tier Royalty payment percentage to be made on cumulative sales within the 1st tier cumulative sales range, under the terms of the non-exclusive license agreement. Royalty payment percentage of cumulative sales over range Royalty payment percentage of sales 2nd tier Percentage of royalty payment to be made on cumulative sales over cumulative sales range 2nd tier, under the terms of the non-exclusive license agreement. Royalty expense Royalty Expense Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Research and Development Arrangement Contract to Perform for Others by Product [Axis] Research and Development Arrangement Contract to Perform for Others by Product [Axis] Research and Development Arrangement Contract to Perform for Others by Product [Axis] Research and Development Arrangement Contract to Perform for Others by Product [Domain] Research and Development Arrangement Contract to Perform for Others by Product [Domain] [Domain] for Research and Development Arrangement Contract to Perform for Others by Product [Axis] Antibody Collaboration Antibody Collaboration [Member] In November 2007, the Company entered into a global, strategic collaboration (the Antibody Collaboration) with Sanofi to discover, develop, and commercialize fully human monoclonal antibodies. Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Previously Reported [Member] Scenario, Previously Reported [Member] Scenario, Forecast [Member] Scenario, Forecast [Member] Restatement Adjustment [Member] Restatement Adjustment [Member] Revised [Member] Scenario, Actual [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Stock Common Stock [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Long-Term Incentive Plan 2014 [Member] Long-Term Incentive Plan 2014 [Member] Long-Term Incentive Plan 2014 Long-Term Incentive Plan 2000 [Member] Long-Term Incentive Plan 2000 [Member] Long-Term Incentive Plan 2000 [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Stock options Employee Stock Option [Member] Phantom stock Phantom Share Units (PSUs) [Member] Non-performance based stock options Non-Performance Based Stock Options [Member] A stock option whose vesting is not contingent upon performance achievements. Performance-based stock options Performance Shares [Member] Restricted stock Restricted Stock [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Share-based Compensation Selling, general, and administrative Selling, General and Administrative Expense Deferred Tax Assets, Net, Noncurrent Deferred Tax Assets, Net, Noncurrent Number of shares authorized for issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period 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. Period within vesting date that awards may be received Share Based Compensation Arrangement By Share Based Payment Award Period From Vesting Date Awards May Be Received The period (in days) from the vesting date during which the Participant has the right to receive, an amount, in cash and/or shares of the Company's Common Stock as determined by the Committee, equal to the sum of the fair market value of a share of Common Stock on the date such share of Phantom Stock vests and the aggregate amount of cash dividends paid with respect to a share of Common Stock during the period from the grant date of the share of Phantom Stock to the date on which the share vests. Number of shares available for future grants Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Number of shares outstanding at beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Number of shares granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Number of shares forfeited Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Number of shares expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Number of shares exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Number of shares outstanding at end of period 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] Weighted average exercise price - outstanding at beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted average exercise price - granted Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Weighted average exercise price - forfeited Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Weighted average exercise price - expired Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Weighted average exercise price - exercised Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Weighted average exercise price - outstanding at end of period Weighted average remaining contractual term (in years) - outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Instrinsic value - outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Number of shares vested and expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Weighted average execise price - vested and expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price 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 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 Number of shares exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted average exercise price - exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted average remaining contractual term - exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Intrinsic value - exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Total intrinsic value - of stock options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Exercise Price Equal to Market Price [Abstract] Exercise price equal to Market Price [Abstract] -- None. No documentation exists for this element. -- Number of Options Granted (shares) Weighted Average Exercise Price (dollars per share) Weighted Average Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Employee Service Share-based Compensation, Aggregate Disclosures [Abstract] Employee Service Share-based Compensation, Aggregate Disclosures [Abstract] Non-cash stock-based compensation expense Allocated Share-based Compensation Expense Unrecognized stock-based compensation cost, net of estimated forfeitures Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted average period for recognition of total unrecognized compensation expense (in years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected lives from grant date Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Number of shares outstanding at beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Number of shares granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Number of shares vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Number of shares outstanding at end of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Weighted average grant date fair value at beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted average grant date fair value - granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted average grant date fair value - vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted average grant date fair value at end of period Assets Assets Additional paid-in capital Additional Paid in Capital Retained Earnings (Accumulated Deficit) Retained Earnings (Accumulated Deficit) Stockholders' Equity Attributable to Parent Stockholders' Equity Attributable to Parent Liabilities and Equity Liabilities and Equity Costs and Expenses Costs and Expenses Operating Income (Loss) Operating Income (Loss) Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income Tax Expense (Benefit) Income Tax Expense (Benefit) Net Income Net Income (Loss) Attributable to Parent Earnings Per Share, Basic Earnings Per Share, Basic Net income per share - diluted Earnings Per Share, Diluted Increase (Decrease) in Deferred Income Taxes Increase (Decrease) in Deferred Income Taxes Share Based Compensation Arrangement By Share Based Payment Award Options Nonvested Number Share Based Compensation Arrangement By Share Based Payment Award Options Nonvested Number The number of non-vested and outstanding stock (or unit) options, as of the balance sheet date. Deferred Revenue Disclosure [Abstract] Deferred Revenue, by Arrangement, Disclosure Deferred Revenue, by Arrangement, Disclosure [Table Text Block] Transactions Involving Stock Option Awards Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] 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] 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] Activity Related to Restricted Stock Awards Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Collaboration Agreement [Abstract] Collaboration Agreement Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Mitsubishi Tanabe Pharma Corporation (MTPC) [Member] Mitsubishi Tanabe Pharma Corporation (MTPC) [Member] Mitsubishi Tanabe Pharma Corporation (MTPC) [Member] Type of Arrangement and Non-arrangement Transactions [Axis] Type of Arrangement and Non-arrangement Transactions [Axis] Arrangements and Non-arrangement Transactions [Domain] Arrangements and Non-arrangement Transactions [Domain] Collaborative Arrangement [Member] Collaborative Arrangement [Member] Collaboration Agreements [Line Items] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Deferred Revenue, Additions Deferred Revenue, Additions Future development milestone payment the Company is eligible to receive Future development milestone payment the Company is eligible to receive Future development milestone payment the Company is eligible to receive. Contingent payments Company could receive Contingent payments Company could receive The amount of contingent payments the Company is entitled to receive related to development and other milestones achieved by MTPC. Collaborative Arrangement, Purchase Price, Percentage of Net Product Sales Collaborative Arrangement, Purchase Price, Percentage of Net Product Sales The percentage of net sales of the product the Company will supply the product to MTPC (subject to adjustment in certain circumstances). Collaborative Arrangement, Additional Eligible Aggregate Payments Collaborative Arrangement, Additional Eligible Aggregate Payments The aggregate amount of additional payments the Company is entitled to receive upon the achievement of specified annual net sales amounts. Starting specified levels of annual sales at which sales milestone payments may be received Starting specified levels of annual sales at which sales milestone payments may be received The starting specified levels of total annual sales within the MTPC Territories at which the Company is eligible to receive additional payments. Payables and Accruals [Abstract] Accounts Payable and Accrued Liabilities, Current [Abstract] Accounts payable Accounts Payable, Trade, Current Accrued payroll and related costs Employee-related Liabilities, Current Accrued clinical trial expense 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). Accrued sales-related charges, deductions and royalties Accrued sales-related charges, deductions and royalties Carrying value as of the balance sheet date of sales-related charges, deductions and obligations incurred through that date and accrual for royalties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Other accrued expenses and liabilities Other Accrued Liabilities, Current Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities, Current Quarterly Financial Information Disclosure [Abstract] Unaudited Quarterly Results Quarterly Financial Information [Text Block] Property, Plant and Equipment [Abstract] Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Schedule of Research and Development Arrangement, Contract to Perform for Others [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] PD-1 [Member] PD-1 [Member] Programed Cell Death protein 1, or PD-1 ("REGN2810") New Funding [Member] New Funding [Member] The new funding under IO Discovery Agreement. Previous Funding under Antibody Discovery Agreement [Member] Previous Funding under Antibody Discovery Agreement [Member] The funding under IO Discovery Agreement that would have otherwise been available to the Company under the existing Discovery and Preclinical Development Agreement, which will reduce the funding available in the aggregate under the existing Discovery and Preclinical Development Agreement by such amount. IO Agreement [Member] IO Agreement [Member] IO Agreement Immuno-oncology Agreement [Member] Immuno-oncology Agreement [Member] Immuno-oncology Agreement Sanofi Sanofi [Member] Information related to Sanofi. VelociGene Agreement VelociGene Agreement [Member] In August 2008, the Company entered into a separate agreement with Sanofi to use Regeneron's proprietary VelociGene technology platform to supply Sanofi with genetically modified mammalian models of gene function and disease (the VelociGene Agreement). PDGF PDGF [Member] PDGF [Member] Ang2 Ang2 [Member] Ang2 [Member] ZALTRAP Agreement Aflibercept Agreement [Member] In September 2003, the Company entered into a collaboration agreement (the Aflibercept Agreement) with Aventis Pharmaceuticals Inc. (predecessor to Sanofi), to jointly develop and commercialize aflibercept. IO Discovery Agreement [Member] IO Discovery Agreement [Member] In July 2015, the Company entered into a collaboration agreement (Immuno-Oncology agreement) with Sanofi, to jointly develop and commercialize Immuno-Oncology programs. IO License and Collaboration Agreement [Member] IO License and Collaboration Agreement [Member] In July 2015, the Company entered into a Immuno-oncology License and Collaboration Agreement (the "IO License and Collaboration Agreement") with Sanofi, to jointly develop and commercialize Immuno-oncology products. Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Collaboration Agreement with Sanofi Collaboration Agreement with Sanofi [Member] Collaboration agreement with Sanofi. Accounts receivable - trade, net Accounts Receivable, Net, Current Deferred revenue from Sanofi, current portion Deferred Revenue From Related Party Current The current portion of deferred revenue from related parties as of balance sheet date. Current deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP. 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. Recognition of Deferred Revenue Recognition of Deferred Revenue Common Stock, shares issued (in shares) Common Stock, Shares, Issued Net profit (loss) from commercialization of products under collaboration agreement Net profit (loss) from commercialization of products under collaboration agreement Our share of profits/losses related to commercialization of products by our collaborator based on sales outside the United States. Under the terms of our collaboration agreement, we share profits/losses with our collaborator on commercialization of products. Revenue Recognition, Milestone Method, Revenue Recognized Revenue Recognition, Milestone Method, Revenue Recognized Research and Development Arrangement, Contract to Perform for Others, Compensation Earned Research and Development Arrangement, Contract to Perform for Others, Compensation Earned Contracts Revenue Contracts Revenue Research and Development Asset Acquired Other than Through Business Combination, Written-off Research and Development Asset Acquired Other than Through Business Combination, Written-off License agreement term License agreement term Potential agreement term, from the effective date of agreement. 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. Percentage of development cost for the territory outside the United States to be paid for under the collaboration Percentage of development cost for the territory outside the United States previously required to be paid for under the collaboration Percentage of development cost for the territory outside the United States previously required to be paid for under the collaboration. Deferred Revenue, Revenue Recognized Deferred Revenue, Revenue Recognized Research and Development Expense Research and Development Expense Deferred Revenue, Additions Potential future R&D expenses Potential future R&D expenses The total potential amount of research and development expenses the Company may pay to identify and validate potential immuno-oncology targets and develop therapeutic antibodies against such targets through clinical proof-of-concept. Maximum amount of shared development costs Maximum amount of shared development costs The maximum amount of shared development expenses for PD-1. Revenue from Related Parties Revenue from Related Parties Proceeds from Collaborators Proceeds from Collaborators Amount of milestone payments that may be received relating to marketing approval Amount of milestone payments that may be received relating to marketing approval The amount of milestone payments the Company may receive under the collaboration agreement related to receipt of specified marketing approval. 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. Minimum advance notice required to terminate collaboration agreement Minimum advance notice required to terminate collaboration agreement The minimum advance notice required of the collaborating party to terminate the agreement without cause. Minimum payment received under the agreement Minimum payment received under the agreement The minimum amount of payments received under the agreement. Annual funding maximum of research activities per amended agreement Annual funding maximum of research activities per amended agreement The maximum annual amount of funding for research activities through 2017 per the amended agreement. Reduction of Funding for Research Activities Per Agreement Reduction of Funding for Research Activities Per Agreement Reduction of Funding for Research Activities Per Agreement Funding Maximum of Research Activities Per Agreement Funding Maximum of Research Activities Per Agreement The maximum amount of cost reimbursement the Company will receive, subject to certain annual limits. Additional years to extend the agreement Additional years to extend the agreement Additional years to extend the agreement Substantive milestone payment to the Company Substantive milestone payment to the Company Substantive milestone payment from Collaborators to the Company under certain defined circumstances. Percentage of Trial Costs borne by collaborating party Percentage of Trial Costs borne by collaborating party The percentage of subsequent Shared Phase 3 Trial costs borne by the collaborating party upon receipt of the first positive Phase 3 trial results for a co-developed drug candidate. Percentage of Trial Costs borne by entity Percentage of Trial Costs borne by entity The percentage of subsequent Shared Phase 3 Trial costs borne by the Company upon receipt of the first positive Phase 3 trial results for a co-developed drug candidate. Percentage of trial costs to be reimbursed due to profitability of agreement Percentage of trial costs to be reimbursed due to profitability of agreement The percentage of Shared Phase 3 trial costs to be reimbursed due to profitability of agreement. Excess Share of profit not required to to be applied to reimburse development cost Excess Share of profit not required to to be applied to reimburse development cost The excess percentage of profits from collaboration not required to be used to reimburse development cost in any calendar quarter. 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. 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. 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. 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. Share of losses outside the United States, for collaborating party Share of losses outside the United States, for collaborating party This element represents the share of losses outside the United States for the collaborating party. Share of losses outside the United States, for Company Share of losses outside the United States, for Company This element represents the share of losses outside the United States for the Company. Maximum amount of sales milestone payments if total sales achieve specific levels Maximum amount of sales milestone payments if total sales achieve specific levels The maximum amount of sales milestone payments the Company is eligible to receive when and if total annual sales achieve certain specified levels. 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 Percentage of aggregate net sales to be paid by the related party in such calendar year Percentage of aggregate net sales to be paid by the related party in such calendar year Percentage of aggregate net sales to be paid by the related party in such calendar year. Amount of funding of agreed-upon cost incurred to expand manufacturing capacity Amount of funding of agreed-upon cost incurred to expand manufacturing capacity The amount of funding of agreed-upon costs incurred by the Company to expand its manufacturing capacity. Maximum amount of reimbursement related to capital expenditures Maximum amount of reimbursement related to capital expenditures Maximum amount of reimbursement related to capital expenditures Interest Receivable Amount of capital expenditures which has been received or is receivable The amount of capital expenditure reimbursed by Sanofi which has been received or is receivable. Period of Notice to Opt Out of Further Development and or Commercialization Period of Notice to Opt Out of Further Development and or Commercialization The period of notice (in months) for either party under the agreement to opt-out of further development and/or commercialization of each antibody product which enters development. Period of Notice to Opt Out of Further Development Upon Entering of Joint Development Product Period of Notice to Opt Out of Further Development Upon Entering of Joint Development Product The notice period (in days) that the Company must give to exercise its option to opt-out of further development with respect to each antibody product which enters development. Number of families of novel antibodies Number of families of novel antibodies Number of families of novel antibodies that the Company acquired from Sanofi. Number of Payments the Company made Number of Payments the Company made Number of Payments Other Research and Development Expense Other Research and Development Expense Potential future milestone payments Potential future milestone payments The maximum amount of development milestone payments the Company may pay. Payments for Purchase of Other Assets Payments for Purchase of Other Assets Other Revenue, Net Other Revenue, Net Schedule of Operating Leased Assets [Table] Schedule of Operating Leased Assets [Table] Name of Lease [Axis] Name of Lease [Axis] The name of the lease for which pertinent information is disclosed. Name of Lease [Domain] Name of Lease [Domain] The name of the lease for which pertinent information is disclosed. Facilities - Buildings A and B Facilities Buildings A and B [Member] Facility lease obligations pertaining to office and laboratory facilities in Buildings A and B in Tarrytown, New York. Facilities Building D and E Facilities Building D and E [Member] Facilities Building D and E Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Facilities Building [Member] Equipment Equipment [Member] Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Rent Charges for Utilities, Real Estate Taxes, and Operating Expense Rent Charges for Utilities, Real Estate Taxes, and Operating Expense The total amount of rent charges for utilities, real estate taxes, and operating expense for the period. Operating Leases [Abstract] Leases, Operating [Abstract] Number of new buildings leased Number of new buildings leased The number of newly constructed buildings leased by the Company. For these buildings, the Company is deemed, in substance, to be the owner of the landlord's buildings in accordance with the application of FASB authoritative guidance, and the landlord's costs of constructing these new facilities are required to be capitalized on the Company's books as a non-cash transaction, offset by a corresponding lease obligation on the Company's balance sheet. Lease renewal escalation percentage Annual rent escalation percentage Annual rent escalation percentage - Tarrytown leases Commitments under operating leases [Abstract] Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2015 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2016 Operating Leases, Future Minimum Payments, Due in Two Years 2017 Operating Leases, Future Minimum Payments, Due in Three Years 2018 Operating Leases, Future Minimum Payments, Due in Four Years 2019 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Rent expense under operating leases [Abstract] Operating Leases, Rent Expense, Net [Abstract] Rent expense under operating leases Operating Leases, Rent Expense, Net Tarrytown lease [Abstract] Tarrytown lease [Abstract] Tarrytown lease [Abstract] Legal Matters Legal Matters and Contingencies [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Investments, Debt and Equity Securities [Abstract] Available-for-sale Securities Available-for-sale Securities [Table Text Block] Marketable Securities, Based on Contractual Maturity Dates Investments Classified by Contractual Maturity Date [Table Text Block] Fair Value and Unrealized Losses of Marketable Securities Schedule of Unrealized Loss on Investments [Table Text Block] Document And Entity Information [Abstract] -- None. No documentation exists for this element. -- Entities [Table] Class A Stock Common Class A [Member] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Collaboration revenue Collaboration revenue [Table Text Block] Summary of collaboration revenue [Table Text Block] Schedule of Selected Financial Information - Sanofi Schedule of Selected Financial Information - Sanofi [Table Text Block] Schedule of selected financial information - Sanofi [Table Text Block] Schedule of Selected Financial Information - Bayer Schedule of Selected Financial Information - Bayer [Table Text Block] Schedule of Selected Financial Information - Bayer [Table Text Block] Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Warrant Warrant [Member] Scenario [Axis] Statement [Line Items] Statement [Line Items] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Non-cash compensation expense Loss on Extinguishment of Debt Gains (Losses) on Extinguishment of Debt Other non-cash charges and expenses, net Other Noncash Income (Expense) Increase (Decrease) in Deferred Income Taxes Changes in assets and liabilites Increase (Decrease) in Operating Capital [Abstract] Increase in Sanofi, Bayer HealthCare, and trade accounts receivable Increase (Decrease) in Accounts Receivable Increase in Inventories Increase (Decrease) in Inventories (Increase) decrease in prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Increase (decrease) in deferred revenue Increase (Decrease) in Deferred Revenue Increase in accounts payable, accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Total adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of marketable securities Payments to Acquire Marketable Securities Sales or maturities of marketable securities Proceeds from Sale and Maturity of Marketable Securities Capital expenditures Payments to Acquire Productive Assets Net cash used in by investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from (Repayments of) Long-term Debt and Capital Securities Proceeds from (Repayments of) Long-term Debt and Capital Securities Repayments of convertible senior debt Repayments of Convertible Debt Payments in connection with reduction of outstanding warrants Payments for Repurchase of Warrants Proceeds from issuance of Common Stock Proceeds from Issuance of Common Stock Payments in connection with Common Stock tendered for employee tax obligations Payments Related to Tax Withholding for Share-based Compensation Excess tax benefit from stock-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Net increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of period Cash paid for interest (net of amounts capitalized) Interest Paid, Net Cash paid for income taxes Income Taxes Paid, Net Accounting Policies [Abstract] Estimated useful lives of property, plant, and equipment [Table Text Block] Estimated useful lives of property, plant, and equipment [Table Text Block] Tabular disclosure of the estimated useful lives of property, plant, and equipment. Schedule of Facility Leases [Table] Schedule of Facility Leases [Table] -- None. No documentation exists for this element. -- Facility Lease Obligations [Axis] Facility Lease Obligations [Axis] Facility lease obligations, by facility. Facility Lease Obligations, Name [Domain] Facility Lease Obligations, Name [Domain] The name of the facilities leased under facility lease obligations. Facilities - Building C Facilities Building C [Member] Facility lease obligations pertaining to office and laboratory facilities in Building C in Tarrytown, New York. Schedule of Facility Leases [Line Items] Schedule of Facility Leases [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. 2015 Capital Leases, Future Minimum Payments Due, Next Twelve Months 2016 Capital Leases, Future Minimum Payments Due in Two Years 2017 Capital Leases, Future Minimum Payments Due in Three Years 2018 Capital Leases, Future Minimum Payments Due in Four Years 2019 Capital Leases, Future Minimum Payments Due in Five Years Thereafter Capital Leases, Future Minimum Payments Due Thereafter Total Capital Leases, Future Minimum Payments Due Facility lease obligations [Abstract] Facility lease obligations [Abstract] -- None. No documentation exists for this element. -- Imputed interest rate applicable to facility lease obligation Imputed interest rate applicable to facility lease obligation The imputed interest rate applicable to the facility lease obligation. Interest expense in connection with facility lease obligation Interest expense in connection with facility lease obligation Interest expense recognized during the period in connection with facility lease obligation. Commitments under facility leases [Abstract] Facility Leases, Future Minimum Payments Due [Abstract] -- None. No documentation exists for this element. -- Facility lease obligation, including reimbursements Facility lease obligation, including reimbursements The facility lease obligation balance as of the reporting date. The Company is deemed, in substance, to be the owner of the landlord's buildings; therefore, costs of constructing the facilities that the landlord incurred and reimbursements from the Company's landlord for tenant improvement costs were capitalized, offset by a corresponding facility lease obligation. Technology Licensing Agreements [Abstract] Technology Licensing Agreements [Abstract] Technology Licensing Agreements Technology Licensing Agreements [Text Block] The entire disclosure pertaining to the terms of agreements to allow other parties to utilize the Company's technology, under a licensing arrangement. Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Convertible senior notes Convertible Debt [Member] Credit Facility [Domain] Credit Facility [Domain] Option Indexed to Issuer's Equity, Type [Axis] Option Indexed to Issuer's Equity, Type [Axis] Option Indexed to Issuer's Equity, Type [Domain] Option Indexed to Issuer's Equity, Type [Domain] Call option Call Option [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Treasury Stock, Value Treasury Stock, Value Interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Initial conversion price (in dollars per share) Debt Instrument, Convertible, Conversion Price Percentage of principal value that holders can require Company to repurchase Debt instrument Percentage of principal value that holders can require Company to repurchase The percentage of the principal value that the holders can require the Company to purchase in the event of a "fundamental change". Estimated fair value of the liability component Debt Instrument Convertible Fair Value Of Liability Component The estimated fair value of the liability component of convertible debt as of the date of issuance. Carrying amount of equity component Debt Instrument, Convertible, Carrying Amount of Equity Component Gross proceeds from the issuance of the Notes Proceeds from Issuance of Long-term Debt Effective interest rate used to amortize the discount on the liability component Debt Instrument, Interest Rate, Effective Percentage Net carrying amount of the liability component [Abstract] Net carrying amount of the liability component [Abstract] -- None. No documentation exists for this element. -- Convertible Debt Convertible Debt Unamortized discount Debt Instrument, Unamortized Discount Convertible Notes Payable Convertible Notes Payable Treasury Stock, Shares Treasury Stock, Shares Interest Expense, Debt [Abstract] Interest Expense, Debt [Abstract] Contractual coupon interest rate Interest Expense, Debt, Excluding Amortization Amortization of discount and note issuance costs Amortization of Financing Costs and Discounts Total interest expense Interest Expense, Debt Warrants [Abstract] Warrants and Rights Note Disclosure [Abstract] Strike price of the warrant transaction (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Proceeds received from the Warrant Proceeds from Issuance of Warrants Reduction of number of warrants Reduction of number of warrants Reduction of number of warrants Adjustments to Additional Paid in Capital, Other Adjustments to Additional Paid in Capital, Other Debt Conversion, Converted Instrument, Shares Issued Debt Conversion, Converted Instrument, Shares Issued Treasury Stock, Shares, Acquired Treasury Stock, Shares, Acquired Payments for Repurchase of Warrants warrants outstanding warrants outstanding Number of warrants outstanding Maximum reduction of warrants held by warrant holder Maximum reduction of warrants held by warrant holder Maximum reduction of warrants held by warrant holder pursuant the agreement. Fair Value Adjustment of Warrants Fair Value Adjustment of Warrants Maximum amount of warrant payable Maximum amount of warrant payable Maximum warrant payment amount pursuant to the agreement. Maximum share price for warrant holders to close out hedge position Limit price per share for warrant holders to close out hedge position Limit price per share for warrant holders to close out hedge position pursuant to the agreement. Accounts Payable, Other Accounts Payable, Other Liabilities, Fair Value Adjustment Other Liabilities, Fair Value Disclosure Convertible Debt [Abstract] Convertible Debt [Abstract] Debt Conversion Debt Conversion The principal amount of convertible notes that were surrendered for conversion. If-converted value in excess of principal Debt Instrument, Convertible, If-converted Value in Excess of Principal Purchase of convertible note hedges Purchase of convertible note hedges Adjustments to additonal paid in capital from the cost of the convertible note hedge. Repayments of Convertible Debt Stock Issued During Period, Shares, New Issues Stock Issued During Period, Shares, New Issues Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments Line of Credit Facility [Abstract] Line of Credit Facility [Abstract] Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Expiration Period Line of Credit Facility, Expiration Period Available increase to the credit facility Available increase to the credit facility Maximum available increase to the credit facility Line of Credit Facility, Current Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Executive Stock Purchase Plan [Abstract] Executive Stock Purchase Plan [Abstract] Schedule of Employee Stock Ownership Plan (ESOP) Disclosures [Table] Schedule of Employee Stock Ownership Plan (ESOP) Disclosures [Table] Employee Stock Ownership Plan (ESOP) Disclosures, by Plan [Axis] Employee Stock Ownership Plan (ESOP) Name [Axis] Employee Stock Ownership Plan (ESOP), Plan [Domain] Employee Stock Ownership Plan (ESOP), Plan [Domain] Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] Revenues [Abstract] 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 may include rebates and chargebacks, and distributor-related fees. Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule Of Unrecognized Tax Benefits Roll Forward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement, by Type [Table] Deferred Revenue Arrangement Type [Axis] Deferred Revenue Arrangement Type [Axis] Deferred Revenue Arrangement Type [Domain] Deferred Revenue [Domain] Nonsoftware License Arrangement [Member] Nonsoftware License Arrangement [Member] License Agreement with Astellas Pharma Inc. License Agreement with Astellas Pharma Inc [Member] Category of deferred revenue by arrangement wherein certain rights are granted to Astellas Pharma Inc. under a license agreement to exploit the Company's technology, under which fees received are taken into income as revenue recognition criteria are met. Deferred Revenue Arrangement [Line Items] Deferred Revenue Arrangement [Line Items] Non-exclusive license agreement term Advance payment received due to amended licensing agreement Proceeds from License Fees Received Recognition period for advance payment Recognition period for advance payment The revenue recognition period (in years) of the up-front payment the Company received under the terms of the amended licensing agreement. This payment was deferred upon receipt and will be recognized as revenue ratably, beginning in mid-2011. Future payment to be made under terms of amended licensing agreement Future payment to be made under terms of amended licensing agreement The amount of future payment to be made to the Company in June 2018 under the terms of the amended licensing agreement, unless the license agreement is terminated prior to that date. Number of days of advance written notice to terminate agreement Number of days of advance written notice to terminate agreement The number of days the licensee must provide advance written notice in order to terminate the licensing agreement. Technology licensing revenue Licenses Revenue Deferred Revenue Deferred Revenue Equity [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Net Product Sales Product Sales and Concentration Risk [Text Block] Product Sales and Concentration Risk Disclosure [Text Block] Inventory Disclosure [Abstract] Raw materials Inventory, Raw Materials, Net of Reserves Work in process Inventory, Work in Process, Net of Reserves Finished goods Inventory, Finished Goods, Net of Reserves Deferred costs Other Inventory, Net of Reserves Total Inventories Inventory, Net Inventory write-downs and reserves Inventory Write-down Statement of Financial Position [Abstract] Common Stock ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Marketable securities Marketable Securities, Current Accounts receivable from Sanofi Accounts Receivable, Related Parties, Current Accounts receivable from Bayer HealthCare Accounts and Notes Receivable, Net Inventories Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Marketable securities Marketable Securities, Noncurrent Property, plant, and equipment, at cost, net of accumulated depreciation and amortization Property, Plant and Equipment, Net Deferred tax assets Other assets Other Assets, Noncurrent Total assets LIABILITIES and STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable and accrued expenses Deferred revenue - other, current portion Deferred Revenue, Excluding Amounts from Related Party, Current The carrying amount of other consideration received or receivable as of the balance sheet date that were not recognized as revenue, and which are expected to be recognized as revenue within one year. Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Deferred revenue from Sanofi Deferred Revenue From Related Party Noncurrent The noncurrent portion of deferred revenue from related parties as of balance sheet date. Noncurrent deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP. Deferred revenue - other Deferred Revenue, Excluding Amounts from Related Party, Non-current The noncurrent portion of other deferred revenue as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Facility lease obligations Facility lease obligations noncurrent Represents the noncurrent portion of a lease liability. In connection with the application of FASB authoritative guidance to the Company's lease of newly constructed facilities, the Company is deemed, in substance, to be the owner of the landlord's building; therefore, costs of constructing the facilities that the landlord incurred and reimbursements from the Company's landlord for tenant improvement costs were capitalized, offset by a corresponding lease obligation. Convertible senior notes Convertible Notes Payable, Noncurrent Other long term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 13) Commitments and Contingencies Stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred Stock Preferred Stock, Value, Issued Common stock Common Stock, Value, Issued Retained earnings Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury Stock Total stockholders' equity Total liabilities and stockholders' equity Schedule of Capital Leased Asssets [Table] Schedule of Capital Leased Assets [Table] Capital Leased Assets [Line Items] Capital Leased Assets [Line Items] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Measured on a recurring basis Fair Value, Measurements, Recurring [Member] Classification of Investment [Axis] This element represents the general categories of investments, which may be classified as Unrestricted or Restricted. Classification of Investment [Domain] Provides general categories of investments for which information is required or determined to be disclosed. Unrestricted Unrestricted [Member] Investments whose use is not restricted in whole or in part, by contractual agreements or regulatory requirements. Restricted [Member] Restricted [Member] Investments whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Other than Temporary Impairment Losses, Investments Other than Temporary Impairment Losses, Investments Available-for-sale marketable securities: Available-for-sale Securities [Abstract] Financial Instruments, Owned, Corporate Debt, at Fair Value Financial Instruments, Owned, Corporate Debt, at Fair Value U.S. government and government agency obligations U S Government Obligations Fair Value Disclosure This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. This item represents available-for-sale securities which consist of investments in U.S. government and government agency obligations neither classified as trading or held-to-maturity securities. Municipal Debt Securities, at Carrying Value Municipal Debt Securities, at Carrying Value Available-for-sale Securities, Equity Securities Available-for-sale Securities, Equity Securities Total fair value of available-for-sale marketable securities Available-for-sale Securities Marketable Securities, Unrealized Gain (Loss) Marketable Securities, Unrealized Gain (Loss) Fair Value, Assets, Level 2 to Level 1 Transfers, Amount Fair Value, Assets, Level 2 to Level 1 Transfers, Amount Convertible Debt, Noncurrent Convertible Debt, Noncurrent Fair value of the outstanding notes Convertible Debt, Fair Value Disclosures Liabilities, Current Collaboration and Contract Research Agreements Collaborative Arrangement Disclosure [Text Block] Marketable Securities Marketable Securities [Table Text Block] Schedule of Quarterly Financial Information Schedule of Quarterly Financial Information [Table Text Block] Compensation and Retirement Disclosure [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Employer contribution expense to 401(k) Savings Plan Defined Contribution Plan, Cost Recognized Common Stock contributed to the Savings Plan (in shares) Stock Issued During Period, Shares, Employee Benefit Plan Employee Savings Plan Pension and Other Postretirement Benefits Disclosure [Text Block] Earnings Per Share [Abstract] Basic and Diluted Net Income (Loss) Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Antidilutive Securities Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Entity by Location [Axis] Entity by Location [Axis] Location [Domain] Location [Domain] UNITED STATES UNITED STATES Foreign Geographic Distribution, Foreign [Member] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Current Foreign Tax Expense (Benefit) Current Foreign Tax Expense (Benefit) Total current tax expense Current Income Tax Expense (Benefit) Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Deferred Foreign Income Tax Expense (Benefit) Deferred Foreign Income Tax Expense (Benefit) Total deferred tax (benefit) expense Deferred Income Tax Expense (Benefit) Total income tax expense (benefit) Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] U.S. federal statutory tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State and local income taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Change in state effective rate Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Foreign income tax rate differential Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent Income tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Percent Non-deductible Branded Prescription Drug Fee Effective Income Tax Rate Reconciliation, Deduction, Medicare Prescription Drug Benefit, Percent Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent Other permanent differences Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Components of Deferred Tax Assets and Liabilities [Abstract] Components of Deferred Tax Assets and Liabilities [Abstract] Deferred tax assets: Components of Deferred Tax Assets [Abstract] Net operating loss carryforward Deferred Tax Assets, Operating Loss Carryforwards Fixed assets Deferred Tax Assets, Property, Plant and Equipment Deferred revenue Deferred Tax Assets, Deferred Income Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Income tax credit carryforwards Deferred Tax Assets, Tax Credit Carryforwards Capitalized research and development costs Deferred Tax Assets Deferred Expense Capitalized Research And Development Costs The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to research and development costs capitalized for tax purposes, which can only be realized if sufficient taxable income is generated in future periods to enable the deduction to be taken. Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Other Deferred Tax Assets, Other Deferred tax assets, gross Deferred Tax Assets, Gross Valuation allowance Deferred Tax Assets, Valuation Allowance Deferred tax assets, net Deferred Tax Assets, Net of Valuation Allowance Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Accruals Deferred Tax Liabilities, Deferred Expense, Reserves and Accruals Deferred Tax Liabilities, Property, Plant and Equipment Deferred Tax Liabilities, Property, Plant and Equipment Convertible senior notes Deferred Tax Liabilities, Financing Arrangements Deferred Tax Liabilities, Other Deferred Tax Liabilities, Other Deferred tax liabilities, gross Deferred Tax Liabilities, Gross Deferred Tax Assets, Net Deferred Tax Assets, Net Utilization of net operating loss carryforwards related to exercises of Nonqualified Stock Options and disqualifying dispositions of ISOs, credited to additional paid-in capital Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Other Comprehensive Income (Loss), Tax Other Comprehensive Income (Loss), Tax Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance as of January 1 Unrecognized Tax Benefits Gross increases related to current year tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Unrecognized Tax Benefits, Period Increase (Decrease) Unrecognized Tax Benefits, Period Increase (Decrease) Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Balance as of December 31 Unrecognized Tax Benefits, Interest on Income Taxes Accrued Unrecognized Tax Benefits, Interest on Income Taxes Accrued Long-Term Incentive Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Schedule of Inventory, Current Schedule of Inventory, Current [Table Text Block] Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Statement of Cash Flows Cash Flow, Supplemental Disclosures [Text Block] Marketing Approval Marketing Approval [Member] Marketing Approval [Member] Pricing Approval Pricing Approval [Member] Pricing Approval [Member] starting at sales achievement - $200 million sales achievement - 1st tier [Member] sales achievement - 1st tier [Member] starting at sales achievement - $500 million sales achievement - $500 million [Member] When total aggregate net sales of EYLEA outside the U.S. reaches this level, the Company is eligible to receive the sales milestone. sales achievement - 200 million sales achievement - 200 million [Member] sales achievement - 200 million sales achievement - 100 million sales achievement - 100 million [Member] [Member] sales achievement - 100 million [Member] [Member] Collaboration Agreement with Bayer HealthCare LLC Collaboration Agreement with Bayer HealthCare LLC [Member] Collaboration agreement with Bayer HealthCare LLC. BRVO BRVO [Member] BRVO [Member] Levels of twelve month sales at which sales milestone payments were received Levels of twelve month sales at which sales milestone payments were received - 500 million Aggregate amount of twelve month sales upon which sales milestone were received. Levels of twelve months sales at which sales milestone payments were received - 200 million Levels of twelve months sales at which sales milestone payments were received - 200 million In connection with a November 2013 agreement, the Company received additional sales milestone payments if twelve-month sales of specific commercial supplies of EYLEA outside the U.S. achieve certain specified levels up to this level. level of twelve months sales at which sales milestone payments maybe received - 100 million level of twelve months sales at which sales milestone payments maybe received - 100 million Level of twelve months sales at which sales milestone payments maybe received - 100 million Inventory Inventory Disclosure [Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Building and improvements Building and Building Improvements [Member] Laboratory and other equipment Furniture and Fixtures [Member] Furniture and Fixtures [Member] Deferred tax asset, reclassification Deferred tax asset, reclassification Deferred tax asset, reclassification Reduction in deferred revenue Reduction in deferred revenue Reduction in deferred revenue as a result of a revision to previously issued financial statements. Decrease in total cash from financing Decrease in total cash from financing Decrease in total cash from financing activities related to the tax impact of the prior period revision. Reduction in accounts receivable Reduction in accounts receivable Reduction in accounts receivable as a result of a revision to previously issued financial statements. Reduction in income tax assets, net Reduction in income tax assets, net Reduction in income tax assets, net due to tax impact on prior period adjustment. Concentration risk, percentage Concentration Risk, Percentage Estimated useful life Property, Plant and Equipment, Useful Life Increase in total cash from operating Increase in total cash from operating Increase in total cash from operating activities related to the tax impact of the prior period revision. Reduction in APIC Reduction in APIC Reduction in APIC due to tax impact on prior period adjustment. Revenue Recognition [Abstract] Revenue Recognition [Abstract] Percentage of prompt pay discount the company accrues Percentage of prompt pay discount the company accrues The percentage of the prompt pay discount that the Company accrues that is based on the gross amount of the product invoice, at the time of sale. Research and Development Expense [Abstract] Concentration Risks, Types, No Concentration Percentage [Abstract] Allowance for Doubtful Accounts Receivable, Current Allowance for Doubtful Accounts Receivable, Current Provision for Doubtful Accounts Provision for Doubtful Accounts PDGFR-beta outside the US PDGFR-beta outside the US [Member] PDGFR-beta outside the US Maximum percentage of outstanding shares that may be acquired, under 'standstill' provisions Maximum percentage of outstanding shares that may be acquired, under 'standstill' provisions The maximum percentage of outstanding shares of the Company's Class A Stock and Common Stock that may be acquired under the 'standstill' provisions, in effect after the specified date. Percentage of global development cost to be paid by the collaboration partner under the collaboration Percentage of global development cost to be paid by the collaboration partner under the collaboration Percentage of global development cost to be paid by the collaboration partner under the collaboration Percentage of development milestone payments to be reimbursed Percentage of development milestone payments to be reimbursed Percentage of development milestone payments Bayer HealthCare is obligated to reimburse the Company for payments that the Company makes to Sanofi related to the Company's acquisition of rights to antibodies targeting the PDGF family of receptors. Number of development milestone payments the Company received Number of development milestone payments the Company received Number of development milestone payments the Company received Opt in payment Opt in payment potential opt-in payment the Company is eligible to receive from Bayer HealthCare. Amount of milestone payment that may be received relating to marketing approval Schedule of assets measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Bayer Collaboration Agreement - PDGFR-beta outside the US Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Common Stock, shares authorized (in shares) Common Stock, Shares Authorized Common Stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common Stock, voting rights Common Stock, Voting Rights Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Number of shares of Common Stock purchased Number of shares of Common Stock purchased The number of shares issued of the Company's Common Stock purchased in connection with the Sanofi collaboration agreement. Number of demand rights to require the Company to conduct registered underwritten public offering Number of demand rights to require the Company to conduct registered underwritten public offering Number of demand rights to require the Company to use all reasonable efforts to conduct registered underwritten public offering with respect to shares of the Company's Common Stock held by Sanofi from time to time. Percentage Of Outstanding Shares Or Voting Rights Under Amended Investor Agreement Percentage Of Outstanding Shares Or Voting Rights Under Amended Investor Agreement The percentage of the then outstanding shares or voting rights of the Company's Class A Stock and Common Stock, which if a stock issuance equals or exceeds such amount, the collaborator has not contractually agreed to vote, and cause its affiliates to vote, either as recommended by the Company's board of directors or proportionally with the votes cast by the Company's other shareholders. Percentage Of Outstanding Shares that the Company is required to appoint an individual agreed upon by the Company and the Collaborator to the Company's board of directors Percentage Of Outstanding Shares that the Company is required to appoint an individual agreed upon by the Company and the Collaborator to the Company's board of directors The percentage outstanding shares that the Company is required to appoint an individual agreed upon by the Company and the collaborator to the Company's board of directors. Total convertible senior notes - par Debt Instrument, Face Amount Gains (Losses) on Extinguishment of Debt Statement of Stockholders' Equity [Abstract] Common Class A Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Treasury Stock Treasury Stock [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Balance (shares) Shares, Outstanding Issuance of Common Stock in connection with exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Issuance of Common Stock in connection with exercise of stock options (shares) Common Stock tendered upon exercise of stock options in connection with employee tax obligations Adjustments Related to Tax Withholding for Share-based Compensation Common Stock tendered upon exercise of stock options in connection with employee tax obligations (in shares) Shares Paid for Tax Withholding for Share Based Compensation Issuance of Common Stock in connection with conversion of convertible senior notes Stock Issued During Period, Value, Conversion of Convertible Securities Issuance of Common Stock in connection with conversion of convertible senior notes (in shares) Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution Stock Issued During Period, Value, Employee Benefit Plan Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution (shares) Issuance of restricted Common Stock under Long-Term Incentive Plan Stock Issued During Period, Value, Restricted Stock Award, Gross Issuance of restricted Common Stock under Long-Term Incentive Plan (shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Conversion of Class A Stock to Common Stock (shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Stock-based compensation charges Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Excess tax benefit from stock-based compensation Acquisition of Common Stock in connection with exercise of convertible note hedges Treasury Stock, Value, Acquired, Cost Method Acquisition of Common Stock in connection with exercise of convertible note hedges (in shares) Reduction of warrants Reclassification of warrant liability Reduction of equity component of convertible senior notes Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Balance Balance (shares) Accounts Payable and Accrued Expenses Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Marketable Securities Marketable Securities, Available-for-sale Securities, Policy [Policy Text Block] Accounts Receivable - Trade Trade and Other Accounts Receivable, Policy [Policy Text Block] Inventories Inventory, Policy [Policy Text Block] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Revenue Recognition - Product Revenue Revenue Recognition, Sales of Goods [Policy Text Block] Revenue Recognition - Collaboration Revenue Collaborative Arrangement, Accounting Policy [Policy Text Block] Research and Development Expenses Research and Development Expense, Policy [Policy Text Block] Stock-based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Per Share Data Earnings Per Share, Policy [Policy Text Block] Concentration of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Legal Costs Legal Costs, Policy [Policy Text Block] Fair Value Transfer, Policy Fair Value Transfer, Policy [Policy Text Block] Revenue Disclosure [Table] Revenue Disclosure [Table] 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. ARCALYST Arcalyst Net Product Sales [Member] Revenue during the period derived from a specified product line (ARCALYST), after deducting applicable provisions for discounts, returns, rebates, chargebacks, distribution fees, and other sales-related deductions. Concentration Risk Type [Axis] Concentration Risk Type [Domain] Customer concentration risk Customer Concentration Risk [Member] Concentration Risk by Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Gross Sales Revenue GrossSalesRevenue [Member] GrossSalesRevenue [Member] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Rebates and Chargebacks Rebates and Chargebacks [Member] A valuation allowance for rebates and chargebacks under governmental programs (including Medicaid), which are netted against revenue from product sales. Distribution Related Fees Distribution Related Fees [Member] A valuation allowance for distribution-related fees which are netted against revenue from product sales. 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. Revenue Disclosure [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Branded Prescription Drug Fee Branded Prescription Drug Fee The incremental Branded Prescription Drug Fee charge recorded in the third quarter of 2014 related to final regulations being issued in July 2014 (which differed in some respects from the temporary regulations issued in 2011). Net product sales Sales Revenue, Goods, Net Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] Activity of Sales Related Deductions [Roll Forward] Movement in Valuation Allowances and Reserves [Roll Forward] Balance Valuation Allowances and Reserves, Balance Provision related to current period sales Valuation Allowances and Reserves, Charged to Other Accounts Credits/payments Valuation Allowances and Reserves, Deductions Schedule of Available-for-sale Securities [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] U.S. government and government agency obligations US Treasury and Government [Member] Corporate bonds Corporate Bond Securities [Member] Municipal Bonds [Member] Municipal Bonds [Member] Equity Securities [Member] Equity Securities [Member] Schedule of Available-for-sale Securities [Line Items] Available-for-sale Securities, Gross Realized Gains Available-for-sale Securities, Gross Realized Gains Amortized Cost Basis Available-for-sale Securities, Amortized Cost Basis Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Unrealized (Losses) Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Securities, Debt Maturities, Fair Value [Abstract] Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] Maturities within one year Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Maturities after one year through five years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Maturities after five years through ten years Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Total Available-for-sale Securities, Debt Securities Continuous Unrealized Loss Position, Fair Value [Abstract] Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] Fair Value - Less than 12 Months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Fair Value - 12 Months or Greater Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Fair Value - Total Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Continuous Unrealized Loss Position, Aggregate Losses [Abstract] Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] Unrealized Loss - Less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Unrealized Loss- 12 Months or Greater Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Unrealized Loss - Total Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Available-for-sale Securities, Gross Realized Losses Available-for-sale Securities, Gross Realized Losses Convertible Notes Payable Convertible Notes Payable [Member] Accrued capital expenditures Accrued Capital Expenditures Carrying value as of the balance sheet date of obligations incurred and payable for purchases of fixed assets. Included in accounts payable and accrued expenses. Notes Payable Notes Payable Facility lease obligations recognized Facility lease obligations recognized The facility lease obligations recognized during the period. Schedule of Effect of Fourth Quarter Events [Table] Schedule of Effect of Fourth Quarter Events [Table] PDGFR-beta Quarterly Financial Information Disclosure [Line Items] Effect of Fourth Quarter Events [Line Items] Revenues Revenues Net income per share - basic Net income per share - diluted Substantive milestone payment Up-front payments made to acquire full rights to antibodies Net Income (Loss) Per Share Earnings Per Share [Text Block] Schedule of Accounts Payable and Accrued Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Convertible Debt Debt Disclosure [Text Block] Schedule of Property, Plant and Equipment [Table] New Laboratory and Office Facilities 3821 Laboratory Apparatus and Furniture [Member] New land in Tarrytown, New York Tarrytown, New York [Member] Tarrytown, New York Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Land Land Buildings and Improvements, Gross Buildings and Improvements, Gross Leasehold Improvements, Gross Leasehold Improvements, Gross Construction in Progress, Gross Construction in Progress, Gross Property, plant, and equipment, gross Property, Plant and Equipment, Gross Furniture and Fixtures, Gross Furniture and Fixtures, Gross Less: accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant, and equipment, net Depreciation and amortization expense Costs incurred by the landlord to construct new laboratory and office facilities Costs incurred by the landlord to construct new laboratory and office facilities Costs incurred by the landlord to construct new laboratory and office facilities which are included in PPE Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] Interest Expense Associated with Convertible Notes Convertible Debt [Table Text Block] Commitments and Contingencies Commitments Disclosure [Text Block] EYLEA EYLEA [Member] EYLEA [Member] Deferred revenue, current portion Deferred Revenue, Current Other Collaboration Revenue Other Collaboration Revenue Revenue realized from sharing of profits/losses on commercialized products, reimbursement of research and development expenses, and other transactions with our collaborator Bayer HealthCare during the period. Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Treasury stock, shares outstanding (in shares) Common Stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Facility lease obligation [Table Text Block] Facility lease obligation [Table Text Block] Tabular disclosure of the facility lease obligation. Commitments Under Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Rent Expense Under Operating Leases Schedule of Rent Expense [Table Text Block] Commitments Under Facility Lease Obligations Commitments Under Facility Lease Obligations [Table Text Block] Tabular disclosure of the commitments required in the aggregate and for each of the five succeeding fiscal years under facility lease obligations having noncancelable lease terms. Deferred Revenue Deferred Revenue Disclosure [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Received or receivable from Sanofi Received or receivable from Bayer HealthCare Received for technology license agreement Other Other Deferred Revenue Agreements [Member] Other category of deferred revenue agreements not otherwise specified in the taxonomy. Current portion: Deferred Revenue and Credits, Current [Abstract] Long-term portion: Deferred Revenue and Credits, Noncurrent [Abstract] Deferred revenue, long-term portion Deferred Revenue, Noncurrent Effect of dilutive securities: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted average shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Effect of dilutive securities (in shares): Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Stock options Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Restricted stock Incremental Common Shares Attributable To Nonvested Restricted Shares Nonvested equity-based payment awards that result in incremental common shares. Warrants Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants Dilutive potential shares Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average shares - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Earnings Per Share, Basic and Diluted [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Stock options Restricted stock Convertible senior notes Convertible Debt Securities [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Weighted average number of shares Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Statement of Comprehensive Income [Abstract] Income Statement [Abstract] Income Statement [Abstract] Revenues: Sanofi collaboration revenue Bayer HealthCare collaboration revenue Other revenue Total revenues Expenses: Costs and Expenses [Abstract] Research and development Cost of goods sold Cost of Goods Sold Cost of collaboration and contract manufacturing Cost of manufacturing Total cost related to third-party royalties the Company is obligated to pay based on sales of commercial product by the Company’s collaborators, as well as costs in connection with producing commercial supplies for the Company’s collaborators and others. Total expenses Income from operations Other income (expense): Nonoperating Income (Expense) [Abstract] Investment and other income (expense) Other Nonoperating Income (Expense) Interest expense Interest Expense Loss on Extinguishment of Debt Total other income (expense) Nonoperating Income (Expense) Income before income taxes Income tax expense Net income Weighted average shares outstanding - basic Weighted average shares outstanding - diluted Statements of Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Unrealized gain (loss) on marketable securities, net of tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent