Supplementary disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Net loss Net loss Net Income (Loss) Attributable to Parent Entity Emerging Growth Company Entity Emerging Growth Company Right-of-use assets, net Right-of-use assets Operating Lease, Right-of-Use Asset Short-term investments Debt Securities, Available-for-sale, Current Restructuring Costs Associated with Exit or Disposal Activities or Restructurings, Policy [Policy Text Block] Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Additional default interest rate Debt Instrument, Interest Rate On Default, Percentage Percentage of additional default interest rate on the event of default. Accrued compensation and benefits Employee-related Liabilities, Current Income Statement Location [Axis] Income Statement Location [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Entity Address, Address Line One Entity Address, Address Line One Total cash equivalents and investments, Gross Unrealized Gains Investments And Cash, Accumulated Gross Unrealized Gain Investments And Cash, Accumulated Gross Unrealized Gain Entity Address, Address Line Two Entity Address, Address Line Two Summary of Additional Details of Leases Schedule of Additional Details of Leases [Table Text Block] The tabular disclosure of additional details of the leases. Schedule of Future Debt Payment Obligations Schedule of Maturities of Long-term Debt [Table Text Block] Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Schedule of Changes in Deferred Revenue Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Additional paid-in capital Additional Paid in Capital, Common Stock Entity Filer Category Entity Filer Category Forfeited (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Weighted-average remaining life (years) Operating Lease, Weighted Average Remaining Lease Term Other assets Other Assets, Noncurrent Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Change in Fair Value of Derivative Liability Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Change in estimated fair value of Exit Fee derivative liability Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Document Fiscal Year Focus Document Fiscal Year Focus Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Closing fee Debt Instrument, Closing Fee Debt Instrument, Closing Fee Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Anti-dilutive securities not included in computation of diluted net loss per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Weighted-average discount rate Operating Lease, Weighted Average Discount Rate, Percent Research and development Research and development expenses Research and Development Expense [Member] Sale of Stock [Axis] Sale of Stock [Axis] Liability Class [Axis] Liability Class [Axis] Subsequent Events [Abstract] Subsequent Events [Abstract] Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Upfront payment received Proceeds from License Fees Received Title of Individual [Domain] Title of Individual [Domain] Award Type [Domain] Award Type [Domain] Assets Assets [Abstract] Exercisable (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Loan payable, current portion Loan payable, current portion Loans Payable, Current Derivative Liability Derivative Instruments and Hedging Activities Disclosure [Text Block] KKC Kyowa Kirin Co. Ltd [Member] Represents the information pertaining to Kyowa Kirin Co., Ltd. Granted (shares) Number of awards granted (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively. Preferred Stock, Value, Issued Proceeds from issuance of common stock under equity incentive and stock purchase plans Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised Outstanding balance, beginning (shares) Outstanding balance, ending (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Entity Address, City or Town Entity Address, City or Town Accumulated Deficit Retained Earnings [Member] Potential commercialization milestones Collaborative Arrangement, Potential Commercialization Milestones Collaborative Arrangement, Potential Commercialization Milestones Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Office space area (sq ft) Area of Real Estate Property Contingencies Commitments and Contingencies Disclosure [Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Accounts receivable Increase (Decrease) in Accounts Receivable Right-of-use assets obtained in exchange for lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Entity Interactive Data Current Entity Interactive Data Current Deferred revenue Increase (Decrease) in Deferred Revenue Number of segments Number of Operating Segments Stock-based Compensation [Line Items] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Net loss per share - basic (in dollars per share) Earnings Per Share, Basic 2024 Lessee, Operating Lease, Liability, to be Paid, Year Three Percentage of royalty revenue Percentage of Royalty Revenue Represents percentage of royalty revenue. Outstanding balance, beginning (shares) Outstanding balance, ending (shares) Awards outstanding (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Fair value of Exit Fee derivative liability, beginning Fair value of Exit Fee derivative liability, ending Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Document Type Document Type Number of RSUs Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Current Reporting Status Entity Current Reporting Status Estimated reduction in workforce as percent of total workforce Restructuring And Related Cost, Expected Number Of Positions Eliminated, Percentage Of Workforce Restructuring And Related Cost, Expected Number Of Positions Eliminated, Percentage Of Workforce Commercial paper Commercial Paper [Member] Taxes paid for net share settlement of equity awards Share-based Payment Arrangement, Decrease for Tax Withholding Obligation Cash paid for operating leases Operating Lease, Payments Reduction in workforce Restructuring and Related Cost, Number of Positions Eliminated Total repayment obligations Long-term Debt, Gross After first anniversary through second anniversary of closing date Debt Instrument, Redemption, Period Two [Member] Plan Name [Axis] Plan Name [Axis] Assets: Assets, Fair Value Disclosure [Abstract] Loan payable Long-term Debt Assets, fair value Assets, Fair Value Disclosure Level 1 Fair Value, Inputs, Level 1 [Member] Investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Document Transition Report Document Transition Report Undiscounted cash payment obligations Lessee, Operating Lease, Liability, Payment, Due [Abstract] Potential development and commercialization milestones Collaborative Arrangement, Potential Development And Commercialization Milestones Represents the amount of future development and commercialization milestone under collaborative arrangements. Total liabilities and stockholders’ equity Liabilities and Equity Pending litigation Pending Litigation [Member] Deferred revenue Beginning balance Ending balance Contract with Customer, Liability, Current Proceeds from maturities and redemptions of investments Proceeds from Sale and Maturity of Debt Securities, Available-for-sale Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Lease Arrangements [Axis] Lease Arrangements [Axis] Lease Arrangements Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Liabilities and stockholders’ equity Liabilities and Equity [Abstract] Derivative liability for Exit Fee Exit Fee derivative liability Derivative Financial Instruments, Liabilities [Member] Accounts payable Increase (Decrease) in Accounts Payable Derivative [Line Items] Derivative [Line Items] Net Loss Per Share Earnings Per Share [Text Block] Operating expenses: Operating Expenses [Abstract] Short-term investments Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Issuance of common stock upon exercise of options Stock Issued During Period, Value, Stock Options Exercised Minimum Minimum [Member] 2023 Lessee, Operating Lease, Liability, to be Paid, Year Two Liabilities, fair value Financial and Nonfinancial Liabilities, Fair Value Disclosure Long-term investments: Long-term Investments [Abstract] Preferred stock, shares authorized Preferred Stock, Shares Authorized Short-term investments, Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Trading Symbol Trading Symbol U.S. treasury notes US Treasury Notes Securities [Member] Current liabilities: Liabilities, Current [Abstract] U.S. government-sponsored agency bonds US Government Corporations and Agencies Securities [Member] Issuance of common stock in at-the-market offering Stock Issued During Period, Value, New Issues Operating lease liabilities Increase (Decrease) in Operating Lease Liability General and administrative General and Administrative Expense Restructuring Plan [Domain] Restructuring Plan [Domain] Borrowing Debt Disclosure [Text Block] Beginning balance (shares) Ending balance (shares) Shares, Outstanding Exercisable (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Equity Incentive Plans Share-based Payment Arrangement [Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Issuance of common stock in at-the-market offering (shares) Stock Issued During Period, Shares, New Issues Term of agreement Term Of Agreement Term of agreement. Total operating lease liabilities Operating Lease, Liability Common stock, $0.0001 par value; 300,000,000 shares authorized; 106,771,584 and 93,599,975 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively. Common Stock, Value, Issued Other (expense) income, net Nonoperating Income (Expense) Average Remaining Vesting Period (Years) Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Outstanding balance, beginning (in dollars per share) Outstanding balance, ending (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Number of options to extend Lessee, Operating Lease, Number Of Renewal Options Lessee, Operating Lease, Number Of Renewal Options Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Commitments and contingencies (Note 12) Commitments and Contingencies Future payment obligations Long-term Debt, Fiscal Year Maturity [Abstract] Subsequent Event [Table] Subsequent Event [Table] Leases Lessee, Operating Leases [Text Block] Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Prepayment premium (as a percent) Debt Instrument, Prepayment Fee, Percentage The percentage of fee payable on prepayment of debt. Remainder of 2021 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Payments made per agreement Payments of Uncharged License Fees Represents the cash outflow from payments of uncharged license fees. Threshold percentage of net sales for tiered royalties Threshold Percentage of Sales For Tiered Royalties Represents the threshold percentage of net sales for tiered royalties. Cash and cash equivalents: Cash and Cash Equivalents, at Carrying Value [Abstract] 2020 Open Market Sales Agreement Open Market Sales Agreement 2020, At The Market Offering [Member] Open Market Sales Agreement 2020, At The Market Offering Document Period End Date Document Period End Date PRSUs Performance Based Restricted Stock Units [Member] This member stands for performance-based restricted stock units. Total operating expenses Costs and Expenses Class of Stock [Axis] Class of Stock [Axis] Entity Registrant Name Entity Registrant Name Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Imputed interest expenses Lessee, Operating Lease, Liability, Undiscounted Excess Amount Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Comprehensive loss: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Financial Instrument [Axis] Financial Instrument [Axis] Total revenues Revenue Revenue from Contract with Customer, Excluding Assessed Tax Fosun Pharma Shanghai Fosun Pharmaceutical Industrial Development [Member] Represents Shanghai Fosun Pharmaceutical Industrial Development. Knight Agreement License Agreement Development Commercialization Distribution In Canada [Member] Agreement for the development, commercialization and distribution fo tenapanor in Canada. The Knight Agreement. Stock options Share-based Payment Arrangement, Option [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Issuance of common stock for services Stock Issued During Period, Value, Issued for Services Common Stock Common Stock [Member] Loss from operations Operating Income (Loss) Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Current portion of operating lease liability Current portion of lease liabilities Less: Current portion of operating lease liability Operating Lease, Liability, Current Short-term investments, Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Organization and Basis of Presentation Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Collaboration and Licensing Agreements Collaborative Arrangement Disclosure [Text Block] ESPP Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan [Member] Stock-based compensation Share-based Payment Arrangement, Noncash Expense Restructuring Restructuring and Related Activities Disclosure [Text Block] Additional Paid-In Capital Additional Paid-in Capital [Member] Cash and cash equivalents Cash and cash equivalents, Amortized Cost Cash and Cash Equivalents, at Carrying Value Depreciation expense Depreciation Weighted-average sales price per share Sale Of Stock, Weighted-Average Price Per Share Sale Of Stock, Weighted-Average Price Per Share Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents [Abstract] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Notice period for impacted employees cash payments and benefits Restructuring And Related Cost, Impacted Employees Term For Cash Payments And Benefits Restructuring And Related Cost, Impacted Employees Term For Cash Payments And Benefits AstraZeneca Termination Agreement AstraZeneca Termination Agreement [Member] AstraZeneca Termination Agreement Accrued and other liabilities Increase (Decrease) in Accrued Liabilities Arrangements and Non-arrangement Transactions [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Fremont facility amendment Facility, Fremont California [Member] Facility, Fremont California Issuance of common stock for services Stock Issued Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Total liabilities Liabilities Award Type [Axis] Award Type [Axis] Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Percentage of non-royalty revenue Percentage of non royalty revenue Represents percentage of non-royalty revenue. Summary of Undiscounted Cash Payment Obligations for Operating Lease Liabilities Lessee, Operating Lease, Liability, Maturity [Table Text Block] Total stockholders’ equity Beginning balance Ending balance Stockholders' Equity Attributable to Parent Estimated restructuring charges expected to be incurred Restructuring and Related Cost, Expected Cost Remaining Issuance of common stock for services (shares) Stock Issued During Period, Shares, Issued for Services Existence of option to extend Lessee, Operating Lease, Existence of Option to Extend [true false] Common stock, shares issued Common Stock, Shares, Issued Preferred stock, shares issued Preferred Stock, Shares Issued Product supply revenue Product Supply Revenue [Member] Product Supply Revenue Other revenue Other Product Or Services Revenue [Member] Represents the information pertaining to revenues from other product or services. Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Commission on sale of stock per agreement (percent) Stock Issuance Cost, Commission, Percent Stock Issuance Cost, Commission, Percent Operating lease liability, net of current portion Operating lease liability, net of current portion Operating Lease, Liability, Noncurrent Measurement Frequency [Domain] Measurement Frequency [Domain] Term loan face amount Debt Instrument, Face Amount Interest expense Interest Expense Accrued compensation and benefits Increase (Decrease) in Employee Related Liabilities Collaborative development revenue Collaborative Development [Member] Collaborative Development [Member] Chief Commercial Officer Chief Commercial Officer [Member] Chief Commercial Officer City Area Code City Area Code Purchase price (in dollars per share) Share Price Accumulated deficit Retained Earnings (Accumulated Deficit) Litigation Case [Domain] Litigation Case [Domain] RSUs Restricted Stock Units (RSUs) [Member] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Final fee due upon maturity, acceleration, prepayment, or termination (percent) Debt Instrument, Fee Due Upon Maturity, Acceleration, Prepayment, Termination, Percentage Debt Instrument, Fee Due Upon Maturity, Acceleration, Prepayment, Termination, Percentage Issuance of common stock under employee stock purchase plan (shares) Number of shares issued under ESPP Stock Issued During Period, Shares, Employee Stock Purchase Plans AstraZeneca Astrazeneca [Member] Represents information pertaining to AstraZeneca. Term of payment of license fee, first installment Term Of Payment Of License Fee, First Installment Term of payment of first installment fee. Other-than-temporary impairment Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale Fair value analysis, percentage change in probability of occurrence Fair Value Sensitivity Analysis, Change In Probability Of Occurrence, Percentage Fair Value Sensitivity Analysis, Change In Probability Of Occurrence, Percentage Shares sold under agreement Equity Sales Agreement, Shares Issued Since Inception Equity Sales Agreement, Shares Issued Since Inception Income Statement [Abstract] Income Statement [Abstract] Amendment Flag Amendment Flag Number of separate collaborative agreements Number Of Separate Collaborative Agreements Number of separate collaborative agreements. Asset Class [Domain] Asset Class [Domain] Schedule of Changes in Fair Value of Derivative Liability Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Second installment of upfront license fees Collaboration And Licensing Agreements, Upfront License Fees, Second Installment Collaboration And Licensing Agreements, Upfront License Fees, Second Installment Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Provision for income taxes Income Tax Expense (Benefit) Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Equity Components [Axis] Equity Components [Axis] Schedule of Securities Classified as Cash, Cash Equivalents and Investments Cash, Cash Equivalents and Investments [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Total current assets Assets, Current Sale of Stock [Domain] Sale of Stock [Domain] Total undiscounted operating lease payments Lessee, Operating Lease, Liability, to be Paid Denominator: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Forfeited (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Fosun Agreement License Agreement Development Commercialization Distribution In China [Member] Agreement for the development, commercialization and distribution of tenapanor in China. The Fosun Agreement. Non-current deferred revenue Change In Contract With Customer Liability, Noncurrent, Rollforward [Roll Forward] Change In Contract With Customer Liability, Noncurrent, Rollforward Entity File Number Entity File Number Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] 2017 KKC Agreement License Agreement Development Commercialization Distribution In Japan [Member] Agreement for the development, commercialization and distribution of tenapanor in Japan. The 2017 KKC Agreement. Product and Service [Axis] Product and Service [Axis] Workforce realignment Workforce Realignment [Member] Workforce Realignment Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Small Business Entity Small Business Restructuring Plan [Axis] Restructuring Plan [Axis] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Amortization of deferred compensation for services Amortization of Deferred Charges Chief Executive Officer Chief Executive Officer [Member] Long-term investments, Gross Unrealized Gains Long Term Investments, Accumulated Gross Unrealized Gain Long Term Investments, Accumulated Gross Unrealized Gain Equity Component [Domain] Equity Component [Domain] After second anniversary to maturity date Debt Instrument, Redemption, Period Three [Member] 2022 Lessee, Operating Lease, Liability, to be Paid, Year One 2021 Open Market Sales Agreement Open Market Sales Agreement 2021, At The Market Offering [Member] Open Market Sales Agreement 2021, At The Market Offering Non-cash interest associated with debt discount accretion Amortization of Debt Discount (Premium) Statement [Line Items] Statement [Line Items] Litigation Case [Axis] Litigation Case [Axis] Right-of-use assets and lease liabilities Assets and Liabilities, Lessee [Abstract] Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Prepayment due Increases to amounts invoiced for which cash has been received Contract With Customer, Liability, Increase For Amounts Invoiced Contract With Customer, Liability, Increase For Amounts Invoiced Short-term investments, Fair Value Debt Securities, Available-for-sale 2019 KKC Agreement Research Collaboration And Option Agreement [Member] Pertaining to the research collaboration and option agreement for research associated with identifying two pre-clinical compounds. The 2019 KKC AGreement. Counterparty Name [Domain] Counterparty Name [Domain] 2025 Lessee, Operating Lease, Liability, to be Paid, Year Four Debt Disclosure [Abstract] Debt Disclosure [Abstract] Potential development milestones Collaborative Arrangement, Potential Development Milestones Collaborative Arrangement, Potential Development Milestones Entity Address, State or Province Entity Address, State or Province Loss before provision for income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Level 2 Fair Value, Inputs, Level 2 [Member] Cash, Cash Equivalents and Investments Cash, Cash Equivalents, and Short-term Investments [Text Block] Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Deferred revenue, non-current Beginning balance Ending balance Contract with Customer, Liability, Noncurrent Short-term investments, Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Lease Arrangements [Domain] Lease Arrangements [Domain] Lease Arrangements [Domain] Loan payable, net of current portion Loans Payable, Noncurrent Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Purchases of investments Payments to Acquire Short-term Investments Use of Estimates Use of Estimates, Policy [Policy Text Block] Schedule of Computation of Net Loss Per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Granted (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Entity Shell Company Entity Shell Company Asset Class [Axis] Asset Class [Axis] Local Phone Number Local Phone Number Summary of Stock-Based Compensation Expense Recognized Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Proceeds from issuance of common stock in at-the-market offering, net of issuance costs Proceeds from Issuance of Common Stock Total assets Assets Board of directors Director [Member] Plan Name [Domain] Plan Name [Domain] Common stock, shares authorized Common Stock, Shares Authorized Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Numerator: Net Income (Loss) Attributable to Parent [Abstract] Principal repayment Repayments of Secured Debt Title of Individual [Axis] Title of Individual [Axis] Schedule of Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Research and development Research and Development Expense Products and Services [Domain] Product and Service [Domain] Derivative Contract [Domain] Derivative Contract [Domain] Term of lease extension Lessee, Operating Lease, Renewal Term Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Summary of Total Unrecognized Stock-Based Compensation Expense, Net of Estimated Forfeitures Share-based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Cash Cash [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Litigation Status [Axis] Litigation Status [Axis] Agreed amount for exit fee upon change of control or regulatory approval Derivative Liability, Notional Amount Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Summary of Lease Costs Lease, Cost [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Entity Tax Identification Number Entity Tax Identification Number Subsequent Event [Line Items] Subsequent Event [Line Items] Lease Contractual Term [Domain] Lease Contractual Term [Domain] Commercial paper Commercial Paper, Not Included with Cash and Cash Equivalents [Member] Accrued expenses and other current liabilities Accrued Liabilities and Other Liabilities Less: Unaccreted value of final fee Debt Instrument, Fee Amount Shares used in computing net loss per share - basic Weighted average common shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Net loss per share - diluted (in dollars per share) Earnings Per Share, Diluted Non-cash lease expense Operating Lease, Right-of-Use Asset, Amortization Expense Knight Knight Therapeutics Inc [Member] Represents information pertaining to Knight Therapeutics Inc. Cash paid for income taxes Income Taxes Paid, Net Subsequent Events Subsequent Events [Text Block] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Lease costs Lease, Cost [Abstract] Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Cost of revenue Cost of Revenue Estimated reduction in workforce Restructuring and Related Cost, Expected Number of Positions Eliminated Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Chief Financial Officer Chief Financial Officer [Member] Term Loan Loans Payable [Member] Collaboration and Licensing Agreements Collaboration and Licensing Agreements n/a Corporate bonds Corporate Debt Securities [Member] Fair Value Measurements Fair Value Disclosures [Text Block] Restructuring charges Restructuring Charges Accounts payable Accounts Payable, Current Summary of Fair Value of Financial Assets and Liabilities Measured or Disclosed on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Accumulated Other Comprehensive Income AOCI Attributable to Parent [Member] Current deferred revenue Change In Contract With Customer Liability, Current, Rollforward [Roll Forward] Change In Contract With Customer Liability, Current, Rollforward Common stock, shares outstanding Common Stock, Shares, Outstanding Long-term investments Long-term Investments Financial Instruments [Domain] Financial Instruments [Domain] Derivative [Table] Derivative [Table] Revenues: Revenues [Abstract] Restructuring and Related Activities [Abstract] Issuance of common stock upon vesting of restricted stock units (shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Lease Contractual Term [Axis] Lease Contractual Term [Axis] Fair value analysis, effect on fair value based on 10% change in probability of occurrence Fair Value Sensitivity Analysis, Ten Percent Change In Probability Of Occurrence, Effect On Valuation Fair Value Sensitivity Analysis, Ten Percent Change In Probability Of Occurrence, Effect On Valuation Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Income Statement Location [Domain] Income Statement Location [Domain] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Supplementary disclosure of non-cash activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Maximum potential payment per agreement Collaborative Arrangement, Potential Payment Per Termination Agreement, Maximum Collaborative Arrangement, Potential Payment Per Termination Agreement, Maximum Upfront license fees Collaboration And Licensing Agreements, Upfront License Fees Collaboration And Licensing Agreements, Upfront License Fees Contingencies [Line Items] Loss Contingencies [Line Items] Property and equipment, net Property, Plant and Equipment, Net Putative securities class action lawsuit Putative Securities Class Action Lawsuit [Member] Putative Securities Class Action Lawsuit Total cash equivalents and investments, Amortized Cost Investments and Cash Long-term investments, Amortized Cost Long Term Investments, Amortized Cost Long Term Investments, Amortized Cost Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Debt Instrument [Line Items] Debt Instrument [Line Items] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Potential cash bonus per retention agreement Retention Agreement, Potential Cash Bonus, Amount Retention Agreement, Potential Cash Bonus, Amount Document Quarterly Report Document Quarterly Report Total cash equivalents and investments, Fair Value Investments And Cash, Fair Value Disclosure Investments And Cash, Fair Value Disclosure Contingent liabilities Loss Contingency Accrual Outstanding balance, beginning (in dollars per share) Outstanding balance, ending (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Liabilities: Liabilities, Fair Value Disclosure [Abstract] Stock-based compensation expense Share-based Payment Arrangement, Expense Weighted Average Value at Grant Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Amortization of (discount) premium on investment securities Accretion (Amortization) of Discounts and Premiums, Investments Amortization of deferred financing costs Amortization of Debt Issuance Costs Counterparty Name [Axis] Counterparty Name [Axis] Common stock Common Class A [Member] Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Current assets: Assets, Current [Abstract] Prior to first anniversary of closing date Debt Instrument, Redemption, Period One [Member] Leases [Abstract] Leases [Abstract] Entity Central Index Key Entity Central Index Key Security Exchange Name Security Exchange Name Cash and cash equivalents, Fair Value Cash and Cash Equivalents, Fair Value Disclosure Issuance of common stock upon exercise of options (shares) Exercised (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Thereafter Lessee, Operating Lease Liability, Payments Due After Year Four Lessee, Operating Lease Liability, Payments Due After Year Four Shares used in computing net loss per share - diluted Weighted average common shares outstanding - diluted Weighted Average Number of Shares Outstanding, Diluted Recurring Fair Value, Recurring [Member] Change in derivative liabilities Increase (Decrease) in Derivative Liabilities Cash, cash equivalents and marketable securities Cash, Cash Equivalents, and Short-term Investments Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Schedule of Stock Option Activity Share-based Payment Arrangement, Option, Activity [Table Text Block] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Officer Officer [Member] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Issuance of common stock under employee stock purchase plan Proceeds from ESPP Stock Issued During Period, Value, Employee Stock Purchase Plan Unrealized (losses) gains on available-for-sale securities Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value General and administrative General and administrative expense General and Administrative Expense [Member] Exit Fee derivative Other Contract [Member] Long-term investments, Fair Value Long Term Investments, Fair Value Long Term Investments, Fair Value Total current liabilities Liabilities, Current Class of Stock [Domain] Class of Stock [Domain] Payments for taxes related to net share settlement of equity awards Payment, Tax Withholding, Share-based Payment Arrangement Reduction in workforce (percent) Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent Litigation Status [Domain] Litigation Status [Domain] Additional details Lessee, Operating Lease, Description [Abstract] Long-term investments, Gross Unrealized Losses Long Term Investments, Accumulated Gross Unrealized Loss Long Term Investments, Accumulated Gross Unrealized Loss Money market funds Money Market Funds [Member] Loss Contingencies [Table] Loss Contingencies [Table] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Less: Unamortized discount and debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Number of defendants Loss Contingency, Number of Defendants Title of 12(b) Security Title of 12(b) Security Waltham facility Facility, Waltham Massachusetts [Member] Facility, Waltham Massachusetts Statement [Table] Statement [Table] Revenue recognized Decreases due to revenue recognized in the period for which cash has been received Contract with Customer Liability Revenue Recognized Cash Received Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received. Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Asset-backed securities Asset-backed Securities [Member] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Investment in continuous unrealized loss position for more than one year Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Unrecognized Compensation Expense Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Statistical Measurement [Axis] Statistical Measurement [Axis] Subsequent event Subsequent Event [Member] Cover [Abstract] Cover [Abstract] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Interest-only payment extension term (in months) Debt Instrument, Interest Payment Extension Term Debt Instrument, Interest Payment Extension Term Licensing revenue License [Member] Adjustments to reconcile net loss to net cash used in operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Operating lease expense Operating Lease, Cost Total cash equivalents and investments, Gross Unrealized Losses Investments And Cash, Accumulated Gross Unrealized Loss Investments And Cash, Accumulated Gross Unrealized Loss Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Closing fee (percent) Debt Instrument, Closing Fee, Percentage Debt Instrument, Closing Fee, Percentage Maximum aggregate offering price Maximum Aggregate Offering Price Amount of maximum aggregate offering price. First installment of upfront license fees Collaboration And Licensing Agreements, Upfront License Fees, First Installment Collaboration And Licensing Agreements, Upfront License Fees, First Installment Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]