Entity Central Index Key Cover [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Interactive Data Current Entity Interactive Data Current Title of 12(b) Security Security12b Title Security Exchange Name Security Exchange Name Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address Address Line1 Entity Address, Address Line Two Entity Address Address Line2 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Statement Of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Other assets Other Assets Noncurrent Total assets Assets Liabilities and stockholders’ equity Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable, accrued expenses and other Accounts Payable And Accrued Liabilities Current Other current liability Other Liabilities Current Total current liabilities Liabilities Current Total liabilities Liabilities Commitments and contingencies Commitments And Contingencies Stockholders’ equity: Stockholders Equity [Abstract] Preferred stock, $0.01 par value: 10,000 shares authorized at March 31, 2020 and December 31, 2019; no shares issued or outstanding at March 31, 2020 or December 31, 2019 Preferred Stock Value Common stock, $0.01 par value: 30,000 shares authorized at March 31, 2020 and December 31, 2019; 13,380 shares issued and outstanding at March 31, 2020 and December 31, 2019 Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders’ equity Liabilities And Stockholders Equity Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, shares issued Preferred Stock Shares Issued Preferred stock, shares outstanding Preferred Stock Shares Outstanding Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Statement Of Income And Comprehensive Income [Abstract] Operating expenses: Operating Expenses [Abstract] Research and development expenses Research And Development Expense General and administrative expenses General And Administrative Expense Gain on sale of assets Gain Loss On Disposition Of Assets1 Total operating (income) expenses Operating Expenses Income (loss) from operations Operating Income Loss Other income and expenses: Nonoperating Income Expense [Abstract] Interest income Investment Income Interest Interest expense Interest Expense Other expense, net Other Nonoperating Income Expense Total other income and expenses Nonoperating Income Expense Net income (loss) Net Income Loss Other comprehensive income: Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent [Abstract] Unrealized gain on marketable securities Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent Other comprehensive income Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Comprehensive income (loss) Comprehensive Income Net Of Tax Net income (loss) per common share - basic and diluted Earnings Per Share Basic And Diluted Weighted-average common shares used to compute basic and diluted net loss per common share Weighted Average Number Of Share Outstanding Basic And Diluted Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-In Capital [Member] Additional Paid In Capital [Member] Accumulated Other Comprehensive Loss [Member] Accumulated Other Comprehensive Income [Member] Accumulated Deficit [Member] Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Balance Balance (in shares) Shares Outstanding Stock-based compensation Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Net income (loss) Profit Loss Balance Balance (in shares) Gain on sale of property plant and equipment. Amortization and accretion on marketable securities. Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and nonemployees. Proceeds from sale of in progress research and development asset. Statement Of Cash Flows [Abstract] Cash flows from operating activities Net Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income (loss) to net cash used in operating activities Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Non-cash interest expense Paid In Kind Interest Depreciation and amortization expense Depreciation Depletion And Amortization Gain on sale of property and equipment Gain Loss On Sale Of Property Plant Equipment Gain on sale of in progress research and development Gain On Sale Of Property Plant And Equipment Amortization and accretion on marketable securities Amortization And Accretion On Marketable Securities Stock-based compensation expense Allocated Share Based Compensation Expense Including Non Employees Loss on equity method investment Gain Loss On Sale Of Equity Investments Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Prepaid expenses and other assets Increase Decrease In Prepaid Deferred Expense And Other Assets Accounts payable, accrued expenses and other Increase Decrease In Accounts Payable And Accrued Liabilities Net cash 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] Proceeds on sale of property and equipment Proceeds From Sale Of Property Plant And Equipment Proceeds from sale of in progress research and development Proceeds From Sale Of In Progress Research And Development Asset Proceeds from maturities and sales of marketable securities Proceeds From Sale And Maturity Of Marketable Securities Net cash provided by investing activities Net Cash Provided By Used In Investing Activities Net increase in cash, cash equivalents and restricted cash Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash, cash equivalents and restricted cash, beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Cash, cash equivalents and restricted cash, end of period Supplemental disclosure of cash flows Supplemental Cash Flow Information [Abstract] Cash paid for income taxes Income Taxes Paid Cash paid for interest Interest Paid Net Organization Consolidation And Presentation Of Financial Statements [Abstract] Nature of the Business Nature Of Operations Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Fair Value Disclosures [Abstract] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Payables And Accruals [Abstract] Accounts Payable, Accrued Expenses and Other Accounts Payable And Accrued Liabilities Disclosure [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Stock-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Earnings Per Share [Abstract] Net Income (Loss) Per Common Share Earnings Per Share [Text Block] Restructuring And Related Activities [Abstract] Restructuring Activities Restructuring And Related Activities Disclosure [Text Block] Accounting Changes And Error Corrections [Abstract] Recent Accounting Pronouncements New Accounting Pronouncements And Changes In Accounting Principles [Text Block] Basis of Presentation Basis Of Accounting Policy Policy [Text Block] Consolidation Consolidation Policy [Text Block] Unaudited Interim Financial Information Comparability Of Prior Year Financial Data Condensed consolidated statements of cash flows. Condensed Consolidated Statements of Cash Flows Condensed Consolidated Statements Of Cash Flows Policy [Text Block] Use of Estimates Use Of Estimates Recent Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Schedule of cash, cash equivalents and restricted cash. Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash Schedule Of Cash Cash Equivalents And Restricted Cash Table [Text Block] Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis Table [Text Block] Schedule of Accounts Payable, Accrued Expenses and Other Schedule Of Accounts Payable And Accrued Liabilities Table [Text Block] Tabular disclosure of employee and nonemployee service share based compensation allocation of recognized period costs. Schedule of Recognized Stock-Based Compensation Expense Schedule Of Employee And Nonemployee Service Share Based Compensation Allocation Of Recognized Period Costs Table [Text Block] Schedule of Outstanding Options Excluded from Computation of Diluted Loss Per Share Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Summary of Charges Related to Restructuring Activities Schedule Of Restructuring And Related Costs [Text Block] Asset sale future milestone payments. Contingent milestone payments receivable. Summary of significant accounting policies. Summary of significant accounting policies. Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Counterparty Name Counterparty Name [Axis] Counterparty Name Repurchase Agreement Counterparty Name [Domain] Ipsen S.A. IpsenSAMember Ipsen S A [Member] Scenario Statement Scenario [Axis] Scenario Scenario Unspecified [Domain] First Line Treatment Of Metastatic Adenocarcinoma Of Pancreas [Member] First Line Treatment Of Metastatic Adenocarcinoma Of Pancreas [Member] After Failure Of First Line Chemotherapy [Member] After Failure Of First Line Chemotherapy [Member] Additional Indication [Member] Additional Indication [Member] Collaborative Arrangement and Arrangement Other than Collaborative Type Of Arrangement [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Arrangements And Nonarrangement Transactions [Member] Asset sale agreement. Asset Sale Agreement [Member] Asset Sale Agreement [Member] Loan agreement. Loan Agreement [Member] Loan Agreement [Member] Legal Entity Legal Entity [Axis] Entity Entity [Domain] Hercules Capital Inc. Hercules Capital Inc [Member] Hercules Capital Inc [Member] Long-term Debt, Type Longterm Debt Type [Axis] Long-term Debt, Type Longterm Debt Type [Domain] Term loan. Term Loan [Member] Term Loan [Member] Subsidiary of the Company. Silver Creek Pharmaceuticals, Inc. [Member] Silver Creek Pharmaceuticals Inc [Member] Property, Plant and Equipment, Type Property Plant And Equipment By Type [Axis] Property, Plant and Equipment, Type Property Plant And Equipment Type [Domain] Laboratory equipment from its research and development operations. Laboratory Equipment [Member] Laboratory Equipment [Member] Fourteener oncology inc member. 14ner Sale [Member] Fourteener Oncology Inc [Member] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Maximum [Member] Maximum [Member] Minimum [Member] Minimum [Member] Milestone achievement one member. Achievement of the Primary Endpoint in the First Registrational Clinical Study of Either MM-121 or MM-111 [Member] Milestone Achievement One [Member] Milestone achievement two member. Achievement of Various Regulatory Approval and Reimbursement-Based Milestones in the United States, Europe and Japan [Member] Milestone Achievement Two [Member] Milestone achievement three member. Achievement Various Cumulative Worldwide Net Sales Targets Between $100.0 million and $300.0 million for MM-121 and MM-111 [Member] Milestone Achievement Three [Member] Ongoing Multi Part Clinical Ongoing Multi Part Clinical [Member] Celator Pharmaceuticals Inc [Member]. Celator Pharmaceuticals Inc [Member] Celator Pharmaceuticals Inc [Member] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Additional payments receivable on achievement of certain milestone events Asset Sale Future Milestone Payments Contingent milestone payment recieved Contingent Milestone Payments Receivable Debt instrument prepayments of debt. Payoff Amount Debt Instrument Prepayments Of Debt Upfront cash payment received. Additional payments receivable on achievement of certain milestone events. Upfront cash payment received Upfront Cash Payment Received Additional payments receivable on achievement of certain milestone events Additional Payments Receivable On Achievement Of Certain Milestone Events Cumulative worldwide net sales target Revenue From Contract With Customer Including Assessed Tax Special cash dividend paid Dividends Common Stock Cash Dividend payable date Dividend Payable Date To Be Paid Day Month And Year Dividend payable, date of record Dividends Payable Date Of Record Day Month And Year Cash payment received. Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants. Transaction expenses. Cash payment received Cash Payment Received Reimbursement of expenses Reimbursement Revenues Transaction expenses Transaction Expenses Accumulated deficit Net income Cash used in operating activities Cash, cash equivalents and marketable securities Cash Cash Equivalents And Short Term Investments Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract] Restricted cash (short-term) Restricted Cash Current Total cash, cash equivalents and restricted cash shown in the condensed consolidated statement of cash flows Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Measurement Frequency Fair Value By Measurement Frequency [Axis] Measurement Frequency Fair Value Measurement Frequency [Domain] Recurring Basis [Member] Fair Value Measurements Recurring [Member] Level 2 [Member] Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value Inputs Level1 [Member] Level 2 [Member] Fair Value Inputs Level2 [Member] Level 3 [Member] Fair Value Inputs Level3 [Member] Asset Class Fair Value By Asset Class [Axis] Asset Class Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class [Domain] Money Market Funds [Member] Money Market Funds [Member] 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] Cash equivalents Cash And Cash Equivalents Fair Value Disclosure Carrying value as of the balance sheet date of obligations incurred through that date arising from ongoing clinical trial activity. Accrued drug purchase costs current. Accounts payable Accounts Payable Current Accrued goods and services Accrued Liabilities Current Accrued clinical trial costs Accrued Clinical Trial Costs Accrued drug purchase costs Accrued Drug Purchase Costs Current Accrued restructuring expenses Restructuring Reserve Current Deferred tax incentives Deferred Credits And Other Liabilities Current Total accounts payable, accrued expenses and other Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] Detail of the plan under which options are granted. Stock Incentive Plan 2011 [Member] Stock Incentive Plan2011 [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Shares of common stock available for grant (in shares) Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Number of Options, Granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Research and Development Expense [Member] Research And Development Expense [Member] General and Administrative Expense [Member] General And Administrative Expense [Member] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Stock-based compensation expense for employee awards Allocated Share Based Compensation Expense Total stock-based compensation expense Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Outstanding Options to Purchase Common Stock [Member] Stock Compensation Plan [Member] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Securities excluded from calculation of diluted loss per share Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Schedule Of Restructuring And Related Costs [Table] Schedule Of Restructuring And Related Costs [Table] Restructuring Plan Restructuring Plan [Axis] Restructuring Plan Restructuring Plan [Domain] November two thousand eighteen corporate restructuring. November 2018 Corporate Restructuring [Member] November Two Thousand Eighteen Corporate Restructuring [Member] Restructuring Type Restructuring Cost And Reserve [Axis] Type of Restructuring Type Of Restructuring [Domain] One-time Termination Benefits [Member] One Time Termination Benefits [Member] Scenario Forecast [Member] Scenario Forecast [Member] Restructuring Cost And Reserve [Line Items] Restructuring Cost And Reserve [Line Items] Restructuring activity, announcement date Restructuring And Related Activities Initiation Date Accrued restructuring expenses Restructuring expenses Restructuring Charges Payments for restructuring Payments For Restructuring Severance Benefits and Related Costs Due to Workforce Reduction [Member] Employee Severance [Member] Accrued Restructuring Expenses Expenses Less: Payments Less: Non-Cash Expenses Restructuring Reserve Settled Without Cash2 Accrued Restructuring Expenses