Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These condensed consolidated financial statements are unaudited and, in the opinion of management, include all adjustments necessary for a fair statement of our financial position and results of operations for the interim periods presented. Such adjustments consisted only of normal recurring items. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). In accordance with GAAP for interim financial reports and the instructions for Form 10-Q and the rules of the Securities and Exchange Commission, certain information and footnote disclosures normally included in annual financial statements have been condensed or omitted. Our accounting policies are described in the Notes to the Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2019 (our “Annual Report”). Interim results are not necessarily indicative of the results of operations for the full year. These interim financial statements should be read in conjunction with our Annual Report.
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements include our accounts and the accounts of our wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates and Assumptions	Use of Estimates and Assumptions The preparation of our condensed consolidated financial statements in conformity with GAAP requires us to make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and the related disclosure of contingent liabilities. We base our estimates on historical experience and on various other assumptions that we believe are reasonable, the results of which form the basis for making judgments about the carrying values of assets, liabilities, equity and the amount of revenues and expenses. The full extent to which the COVID-19 pandemic will directly or indirectly impact our business, results of operations and financial condition, including product sales revenue; product sales allowances and accruals; allowance for expected credit losses; marketable securities; inventory; fair value estimates used to assess impairment of long-lived assets, including goodwill and other intangible assets; debt obligations; certain accrued liabilities, including clinical trial accruals; equity-based compensation expense; and income taxes, inclusive of valuation allowances, will depend on future developments that are highly uncertain, including new information that may emerge concerning COVID-19 and the actions taken to contain or treat its impact, as well as the economic impact on local, regional and national customers and markets. We have made estimates of the impact of COVID-19 within our financial statements and there may be changes to those estimates in future periods. Actual results could differ materially from these estimates.
Concentrations and Significant Customer Information	Concentrations and Significant Customer InformationFinancial instruments which potentially subject us to concentrations of credit risk consist principally of cash and cash equivalents, marketable securities, and accounts receivable. We currently hold our excess cash primarily in institutional money market funds, corporate debt securities, U.S. treasury and government agency securities and certificates of deposit.Our operations are located entirely within the U.S. We focus primarily on developing, manufacturing, and commercializing our products and product candidates. Our net accounts receivable primarily represent amounts due for products sold directly to wholesalers, distributors and specialty pharmacies. Accounts receivable for our products are recorded net of reserves for estimated chargeback obligations, prompt payment discounts and any allowance for expected credit losses.We are currently dependent on a single supplier for certain of our manufacturing processes, including for Feraheme drug substance (produced in two separate facilities) and for our Makena auto-injector product. We have been and may continue to be exposed to a significant loss of revenue from the sale of our products in the event that our suppliers and/or manufacturers are not able to fulfill demand for any reason.
Recently Adopted, Issued and Proposed Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“Topic 326”). We adopted Topic 326 effective January 1, 2020 using a modified retrospective approach. The adoption of Topic 326 did not have a material impact on our condensed consolidated financial statements and accordingly, no transition adjustment was recorded at the adoption date. Under Topic 326, we estimate expected credit losses for our trade receivables held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. We also evaluate any impaired marketable securities against the new impairment model within Topic 326 to determine whether any loss or allowance for credit loss should be recorded at the reporting date. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”) as part of its Simplification Initiative to reduce the cost and complexity in accounting for income taxes. ASU 2019-12 removes certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also amends other aspects of the guidance to help simplify and promote consistent application of GAAP. The guidance is effective for interim and annual periods beginning after December 15, 2020, with early adoption permitted. We adopted ASU 2019-12 effective January 1, 2020. The adoption of ASU 2019-12 did not have a material impact on our condensed consolidated financial statements. RECENTLY ISSUED AND PROPOSED ACCOUNTING PRONOUNCEMENTS From time to time, new accounting pronouncements are issued by FASB or other standard setting bodies that are adopted by us as of the specified effective date. There were no applicable accounting pronouncements issued but not adopted as of June 30, 2020.
Immaterial Revision of Prior Period Financial Information	Immaterial Revision of Prior Period Financial InformationPrior period amounts, specifically net product sales and accrued expenses have been revised to correct a prior period error related to gross-to-net (“GTN”) adjustments for governmental rebates and the related accrual for a certain state program.