Long Term Obligations - Additional Information (Detail)	1 Months Ended			3 Months Ended		9 Months Ended
	Feb. 28, 2019 USD ($)	Feb. 28, 2017 USD ($)	Dec. 31, 2016 USD ($) promissory_note	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	May 31, 2018 USD ($)
Debt Instrument [Line Items]
Gain (loss) on remeasurement of embedded derivatives						$ 3,447,000	$ 3,668,000
Andexxa | HealthCare Royalty Partners and its Affiliates (“HCR”)
Debt Instrument [Line Items]
Accrued interest				$ 39,700,000		$ 39,700,000		$ 22,900,000
Gain (loss) on remeasurement of embedded derivatives					$ 1,900,000		4,300,000
Amount received under royalty sales agreement		$ 50,000,000.0
Additional amount receivable upon U.S. regulatory approval		100,000,000.0
Sales agreement fee		2,000,000.0							$ 5,000,000.0
Additional debt issuance costs		$ 600,000
Funding amount									$ 100,000,000.0
Effective interest rate				14.00%		14.00%
Unamortized debt discount				$ 6,100,000		$ 6,100,000		6,800,000
Ondexxya | HealthCare Royalty Partners and its Affiliates (“HCR”)
Debt Instrument [Line Items]
Gain (loss) on remeasurement of embedded derivatives				400,000		$ 2,100,000
Remeasurement of embedded derivative to fair value, whole provision lapses from funding date, period						30 months
Ondexxya | HealthCare Royalty Partners and its Affiliates (“HCR”) | Secured Term Loan
Debt Instrument [Line Items]
Sales agreement fee				$ 2,800,000		$ 2,800,000
Effective interest rate				12.30%		12.30%
Debt instrument, maturity date	Feb. 28, 2025
Debt instrument, interest rate	9.75%
Debt instrument, covenant description						The loan is secured by substantially all of our assets. The Credit Agreement contains certain covenants that, among others, require us to deliver financial reports at designated times of the year and limit or restrict our ability to incur additional indebtedness or liens, acquire, own or make any investments, pay cash dividends or enter into certain corporate transactions, including mergers and changes of control, and require us to maintain $31.3 million of cash, such amount to be increased if we draw on the second tranche of funding.
Maintain cash increased	$ 31,300,000
Debt instrument default interest rate	12.75%
Debt instrument, accrued interest				$ 1,800,000		$ 3,800,000
Other debt issuance cost				500,000		500,000
Ondexxya | HealthCare Royalty Partners and its Affiliates (“HCR”) | First Tranche | Secured Term Loan
Debt Instrument [Line Items]
Promissory notes, face amount	$ 62,500,000
Ondexxya | HealthCare Royalty Partners and its Affiliates (“HCR”) | Second Tranche | Secured Term Loan
Debt Instrument [Line Items]
Promissory notes, face amount	$ 62,500,000
Ondexxya | Fair Value, Inputs, Level 3 | HealthCare Royalty Partners and its Affiliates (“HCR”)
Debt Instrument [Line Items]
Estimated fair value of long-term debt				71,200,000		71,200,000
Royalty Based Debt | Andexxa | Fair Value, Inputs, Level 3 | HealthCare Royalty Partners and its Affiliates (“HCR”)
Debt Instrument [Line Items]
Estimated fair value of long-term debt				170,600,000		170,600,000		154,200,000
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | United States and EU | Andexxa
Debt Instrument [Line Items]
Percentage of net sales to be paid in each quarter			5.00%
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | Promissory Notes
Debt Instrument [Line Items]
Proceeds from notes payable			$ 50,000,000.0
Number of debt instruments | promissory_note			2
Promissory notes, face amount			$ 65,000,000.0
Promissory notes due date			2024-12
Repayment amount			$ 62,500,000
Repayment date			Dec. 31, 2023
Accrued interest				10,000,000.0		10,000,000.0		7,600,000
Gain (loss) on remeasurement of embedded derivatives				200,000	$ 200,000	1,400,000	$ (600,000)
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | Promissory Notes | Fair Value, Inputs, Level 3
Debt Instrument [Line Items]
Estimated fair value of Notes				$ 50,700,000		$ 50,700,000		$ 53,200,000
Scenario Two | Andexxa | HealthCare Royalty Partners and its Affiliates (“HCR”) | Maximum
Debt Instrument [Line Items]
Percentage of royalty obligated to pay of net worldwide sales		8.46%
Scenario Two | Andexxa | HealthCare Royalty Partners and its Affiliates (“HCR”) | Minimum
Debt Instrument [Line Items]
Percentage of royalty obligated to pay of net worldwide sales		4.19%
Scenario Three | Andexxa | HealthCare Royalty Partners and its Affiliates (“HCR”)
Debt Instrument [Line Items]
Percentage of royalty obligated to pay of net worldwide sales		195.00%
Scenario Three | Andexxa | HealthCare Royalty Partners and its Affiliates (“HCR”) | Maximum
Debt Instrument [Line Items]
Transaction expense		$ 290,600,000
Scenario Three | Andexxa | HealthCare Royalty Partners and its Affiliates (“HCR”) | Minimum
Debt Instrument [Line Items]
Target payment for royalty obligation		$ 150,000,000.0