Collaboration Revenue Disclosure [Abstract] Collaboration Revenue Disclosure [Abstract] Research Collaboration and Licensing Arrangements [Table] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Milestone payment achievement [Axis] Milestone payment achievement [Axis] Milestone payment achievement [Axis] Milestone payment achievement [Domain] Receipt of marketing approval [Domain] [Domain] for Receipt of marketing approval [Axis] Receipt of marketing approval Receipt of marketing approval [Member] Receipt of marketing approval [Member] Sales achievement 1st tier Sales achievement [Member] Sales achievement [Member] Sales achievement 2nd tier Sales achievement 300 million [Member] Sales achievement 300 million [Member] Sale [Axis] Sale [Axis] Sale [Domain] Sale [Domain] Ang2 ANG2 [Member] ANG2 PDGF PDGF [Member] PDGF 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. Collaboration Agreement with Sanofi Collaboration Agreement with Sanofi [Member] Collaboration agreement with Sanofi. Collaboration Agreement with Bayer HealthCare LLC Collaboration Agreement with Bayer HealthCare LLC [Member] Collaboration agreement with Bayer HealthCare LLC. Collaborative Arrangements and Non-collaborative Arrangements [Axis] Collaborative Arrangements and Non-collaborative Arrangements [Axis] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Domain] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Domain] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] ZALTRAP ZALTRAP [Member] ZALTRAP [Member] 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. 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). 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. Research Collaboration and Licensing Arrangements [Line Items] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Number of up-front payments Number of up-front payments Number of up-front payments 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. Under the terms of our collaboration agreement, we share profits/losses with our collaborator on commercialization of products outside of Japan, and we are entitled to a royalty of approximately 35% on annual product sales in Japan, subject to certain potential adjustments. Revenue Recognition, Milestone Method, Revenue Recognized Revenue Recognition, Milestone Method, Revenue Recognized Maximum amount of substantive milestone payments that may be received in major market countries outside the U S Maximum amount of substantive milestone payments that may be received in major market countries outside the U S The maximum amount of substantive milestone payments the Company may receive under the collaboration agreement relating to pricing approvals in major market countries outside the U.S. Starting specified levels of annual sales at which sales milestone payments may be received, 1st tier Starting specified levels of annual sales at which sales milestone payments may be received, 1st tier The starting specified levels of total annual sales outside the United States at which the Company may be eligible to receive sales milestone payments, 1st tier. Number of sales milestones Number of sales milestones Total number of sales milestones received during the period after achieving certain sales levels. Starting specified levels of annual sales at which sales milestone payments may be received, 2nd tier Starting specified levels of annual sales at which sales milestone payments may be received The starting specified levels of total annual sales outside the United States at which the Company may be eligible to receive sales milestone payments, 2nd tier. Period for achieving sales target for milestone payment, rolling basis Period for achieving sales target for milestone payment, rolling basis Cumulative period over which total aggregate sales must exceed certain levels to be entitled to receive sales milestones. Number of families of novel antibodies Number of families of novel antibodies Number of families of novel antibodies that the Company acquired from Sanofi Net profit from commercialization of products under collaboration agreement Net profit from commercialization of products under collaboration agreement Our share of profits related to commercialization of products by our collaborator. Under the terms of our collaboration agreement, we share profits with our collaborator on commercilation of products outside the U.S. (other than Japan) and we are entitled to a royalty on annual product sales in Japan. Research and Development Arrangement, Contract to Perform for Others, Compensation Earned Research and Development Arrangement, Contract to Perform for Others, Compensation Earned Research and Development Asset Acquired Other than Through Business Combination, Written-off Research and Development Asset Acquired Other than Through Business Combination, Written-off Reimbursement of commercial expenses Reimbursement of commercial expenses Reimbursement of other commercial expenses in accordance with our collaboration agreement with Bayer HealthCare. Recognition of Deferred Revenue Recognition of Deferred Revenue Sanofi collaboration revenue Revenue from Related Parties Bayer HealthCare collaboration revenue Other Collaboration Revenue Revenue realized from sharing of profits/losses on commercialized products, cost sharing of development expenses, and other transactions with our collaborator Bayer HealthCare during the period. Substantive Milestone Payments Substantive Milestone Payments The maximum amount of substantive milestone payments the Company may pay. 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 outside the United States achieve certain specified levels. Maximum levels of annual sales for which sales milestone payments may be received Maximum levels of annual sales for which sales milestone payments may be received Maximum levels of total annual sales outside the Uinited States at which the Company may be eligible to receive sales milestone payments. Revenues [Abstract] Revenue Disclosure [Table] Revenue Disclosure [Table] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] GrossSalesRevenue GrossSalesRevenue [Member] GrossSalesRevenue [Member] 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] Concentration Risk Type [Domain] Customer concentration risk Customer Concentration Risk [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] Net product sales Sales Revenue, Goods, Net Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] Concentration risk, percentage Entity-Wide Revenue, Major Customer, Percentage Activity of Sales Related Deductions [Roll Forward] Movement in Valuation Allowances and Reserves [Roll Forward] Balance as of December 31, 2012 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 Balance as of September 30, 2013 Leases [Abstract] Schedule of Capital Leased Assets [Table] Schedule of Capital Leased Assets [Table] New Contract [Axis] New Contract [Axis] New Contract [Domain] New Contract [Domain] New Laboratory and Office Facilities New Laboratory and Office Facilities [Member] Construction of new laboratory and office facilities in Tarrytown, New York in connection with the Company's December 2006 lease, as amended, of these new facilities. Capital Leased Assets [Line Items] Capital Leased Assets [Line Items] Number of new buildings to be constructed Number of new buildings to be constructed Number of new buildings to be constructed Initial term of lease Initial term of lease Initial term of lease Number of Renewal Options Number of Renewal Options Facility Leases, Number of Renewal Options Lease extension terms Lease extension terms Lease extension terms Construction in Progress, Gross Construction in Progress, Gross 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. 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] 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. Commitments and Contingencies Disclosure [Abstract] Legal Matters Legal Matters and Contingencies [Text Block] Document And Entity Information [Abstract] -- None. No documentation exists for this element. -- Entities [Table] Class of Stock [Axis] Class of Stock [Domain] Common Stock Common Stock [Member] 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 Accounting Policies [Abstract] Revenue Recognition, Revenue Reductions Revenue Recognition, Revenue Reductions [Policy Text Block] Income Tax Disclosure [Abstract] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Effective Income Tax Rate, Continuing Operations Effective Income Tax Rate, Continuing Operations Effective Income Tax Rate Reconciliation, Tax Credits, Research Effective Income Tax Rate Reconciliation, Tax Credits, Research Income tax expense Income Tax Expense (Benefit) Loss Contingencies [Table] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Pending litigation Pending Litigation [Member] Litigation Case [Axis] Litigation Case [Axis] Litigation Case Type [Domain] Litigation Case Type [Domain] License agreement with Genentech - EYLEA License Agreement With Genentech [Member] A non-exclusive license agreement with Genentech which requires the Company to make certain payments if certain sales targets are exceeded during the term of the agreement. License agreement with Genentech - ZALTRAP License agreement with Genentech - ZALTRAP [Member] License agreement with Genentech - ZALTRAP [Member] Loss Contingencies by Geographic Area [Axis] Geographic area of each loss contingency that exists as of the balance sheet date. Loss Contingencies by geographic area [Domain] Identification of the geographic area of each loss contingency that exists as of the balance sheet date. Global Global [Member] Global [Member] United States UNITED STATES Loss Contingencies [Line Items] First payment made or may be made upon reaching minimum sales target First payment made or may be 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) The amount of cumulative relevant sales (minimum sales target) which would require the Company to make the first payment. Sales range minimum (1st tier) Sales range minimum (1st tier) The minimum amount of cumulative sales (1st tier) which would require the Company to make royalty payments. Royalty payment percentage of cumulative sale (1st tier) 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. Sales range maximum (1st tier) Sales range maximum (1st tier) The maximum amount of cumulative sales within 1st tier, which will require the Company to make royalty payments. Royalty payment percentage of sales (2nd tier) 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. Cumulative Sales Range (2nd tier) Cumulative Sales Range 2nd Tier The 2nd tier minimum cumulative sales which would require the Company to make royalty payments. Inventory Disclosure [Abstract] Inventory Inventory Disclosure [Text Block] Leases of Lessee Disclosure [Text Block] Leases of Lessee Disclosure [Text Block] Earnings Per Share [Abstract] Basic and Diluted Net Income 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] Schedule of Inventory, Current Schedule of Inventory, Current [Table Text Block] Net Income Per Share Earnings Per Share [Text Block] Payables and Accruals [Abstract] Schedule of Accounts Payable and Accrued Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] 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 bond Corporate Bond Securities [Member] Commercial paper Commercial Paper [Member] Municipal bonds Municipal Bonds [Member] International government agency obligations Foreign Government Debt Securities [Member] Certificates of deposit Certificates of Deposit [Member] Equity securities Equity Securities [Member] U.S. government obligations US Government Debt Securities [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 Restricted [Member] Investments whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. 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, Gross Unrealized Gains Unrealized (Losses) Available-for-sale Securities, Gross Unrealized Losses Available-for-sale Securities, Fair Value Disclosure Available-for-sale Securities, Fair Value Disclosure 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 Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Available-for-sale Securities, Debt Maturities, after Ten Years, 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 Losses [Abstract] Unrealized Loss - Less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses Unrealized Loss - 12 Months or Greater Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses Unrealized Loss - Total Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses Available-for-sale Securities, Gross Realized Losses Available-for-sale Securities, Gross Realized Losses Statement of Financial Position [Abstract] Statement [Table] Class A Stock Common Stock Statement [Line Items] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Marketable securities Marketable Securities, Current Accounts receivable - trade, net Accounts Receivable, Net, Current Accounts receivable from Sanofi Due from Related Parties, Current Deferred tax assets Deferred Tax Assets, Net, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Restricted cash and marketable securities Restricted Cash and Investments, Noncurrent 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 Deferred Tax Assets, Net, Noncurrent Other assets Other Assets, Noncurrent Total assets Assets LIABILITIES and STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities, 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. Deferred Revenue - other, current portion Deferred Revenue, Current Facility lease obligations, current portion Facility Lease Obligations, Current Represents the current 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. 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, Noncurrent 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 Company 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 Commitments and Contingencies Stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock Preferred Stock, Value, Issued Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders' equity Liabilities and Equity Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] U.S. government obligations Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Measured on a recurring basis Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Estimate of Fair Value, Fair Value Disclosure [Member] 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] Fair Value, Inputs, Level 3 Fair Value, Inputs, Level 3 [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] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Number Of Marketable Securities Held Number Of Marketable Securities Held Disclosure of the number of marketable securities held as of the reporting date. Payments to Acquire Marketable Securities Payments to Acquire Marketable Securities Maturity of Marketable Securities Proceeds from Sale and Maturity of Marketable Securities Unrealized Gain (Loss) on Investments Unrealized Gain (Loss) on Securities Total convertible senior notes - par Debt Instrument, Face Amount Interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Fair value of the outstanding notes Convertible Debt, Fair Value Disclosures Accounts Payable and Accrued Expenses Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Statement of Cash Flows [Abstract] Statement [Table] Statement, Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Statement [Line Items] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent 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 Share-based Compensation Non-cash interest expense Non-cash interest expense Interest expense included in net income that results in no cash outflows in the period. Other non-cash charges and expenses, net Other Noncash Income (Expense) Deferred taxes Deferred Income Tax Expense (Benefit) Changes in assets and liabilites Increase (Decrease) in Operating Capital [Abstract] Increase in Sanofi and trade accounts receivable Increase (Decrease) in Accounts Receivable Increase in prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Decrease in deferred revenue Increase (Decrease) in Deferred Revenue (Decrease) 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 (used in) 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 Sales or maturities of marketable securities Purchase of restricted cash and marketable securities Increase (Decrease) in Restricted Cash and Investments 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] Payments in connection with facility and capital lease obligations Repayments of Long-term Capital Lease Obligations 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 (Tax Deficiency) from Share-based Compensation, Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) 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 end of period Fair Value Measurements Fair Value Disclosures [Text Block] Quarterly Financial Data [Abstract] Interim Financial Statements Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Line Items] Subsequent Event [Line Items] Marketable Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] 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 deductions and royalties Carrying value as of the balance sheet date of sales-related 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 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. Legal Costs, Policy Legal Costs, Policy [Policy Text Block] Income Taxes Income Tax Disclosure [Text Block] Statement of Other Comprehensive Income [Abstract] Income Statement [Abstract] Income Statement [Abstract] Bayer HealthCare collaboration revenue Technology licensing Licenses Revenue Other revenue Royalty Revenue Total revenues Revenues Expenses: Costs and Expenses [Abstract] Research and development Research and Development Expense Selling, general, and administrative Selling, General and Administrative Expense Cost of goods sold Cost of Goods Sold Cost of collaboration manufacturing Cost of collaboration manufacturing1 Total costs 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. Total expenses Costs and Expenses Income from operations Operating Income (Loss) Other income (expense): Nonoperating Income (Expense) [Abstract] Investment income Investment Income, Nonoperating Interest expense Interest Expense Total other income (expense) Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Net income Net income per share - basic (in dollars per share) Earnings Per Share, Basic Net income per share - diluted (in dollars per share) Earnings Per Share, Diluted Weighted average shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Weighted average shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Statements of Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Unrealized gain (loss) on marketable securities, net of tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Interest on Convertible Debt, Net of Tax Interest on Convertible Debt, Net of Tax Net Income - diluted Net Income (Loss) Available to Common Stockholders, Diluted Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted average shares - basic (in shares) Effect of dilutive securities (in shares): Weighted Average Number Diluted Shares Outstanding Adjustment [Abstract] Stock options Incremental Common Shares Attributable to 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. Convertible senior notes Incremental Common Shares Attributable to Conversion of Debt Securities Warrants Incremental Common Shares Attributable to Call Options and Warrants Dilutive potential shares Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average shares - diluted (in shares) 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 Stock Options [Member] 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 Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Common Stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common Stock, shares authorized (in shares) Common Stock, Shares Authorized Common Stock, shares issued (in shares) Common Stock, Shares, Issued Common Stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Schedule of assets measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] 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 reserves Inventory Valuation Reserves Inventory write-downs and reserves Inventory Write-down Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Table] 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] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] collaboration revenue with related party collaboration revenue with related party [Table Text Block] Summary of collaboration revenue with related party [Table] Collaboration revenue Collaboration revenue [Table Text Block] Summary of collaboration revenue [Table Text Block] Collaborative Arrangement Disclosure Collaborative Arrangement Disclosure [Text Block] Net Product Sales Revenue And Concentration Risk Disclosure [Text Block] Revenue And Concentration Risk Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Equity Components [Axis] Equity Component [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Accumulated Deficit Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) [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) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period 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 (shares) Shares Paid for Tax Withholding for Share Based Compensation 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) Stock Issued During Period, Shares, Employee Benefit Plan 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 Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Other comprehensive income (loss) Balance Balance (shares)