Liability Related to the Revenue Interest Purchase Agreement - Narrative (Details) - USD ($)				1 Months Ended	3 Months Ended		9 Months Ended
	May 16, 2021	Apr. 26, 2021	Jun. 26, 2019	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Liability Related to the Revenue Interest Purchase Agreement
Deposit to a block account					$ 50,000,000	$ 0	$ 50,000,000	$ 0	$ 0	$ 928,000
Interest expense					13,654,000	4,928,000	32,923,000	13,739,000
Revenue Interest Purchase Agreement (RIPA)
Liability Related to the Revenue Interest Purchase Agreement
Revenue interest liability					247,568,000		247,568,000		$ 176,604,000
Capitalized issuance costs							500,000
Interest expense					10,400,000	$ 4,900,000	23,300,000	$ 13,700,000
RIPA Amendment
Liability Related to the Revenue Interest Purchase Agreement
Loss on modification of debt							100,000
Oberland | Revenue Interest Purchase Agreement (RIPA)
Liability Related to the Revenue Interest Purchase Agreement
Gross proceeds from revenue interest liability			$ 125,000,000.0
Total amount of subsequent installment, subject to RIPA terms and conditions			75,000,000.0
Amount of subsequent installment, subject to regulatory approval			25,000,000.0
Amount of subsequent installment, subject to achievement of sales threshold			50,000,000.0
Milestone amount for worldwide sales to receive the third payment			$ 100,000,000.0
Proceeds from Revenue Interest Purchase Agreement		$ 50,000,000		$ 25,000,000.0
Revenue interest rate which will take effect if annual net sales equals or exceeds the sales threshold by December 31, 2021			2.50%
Initial revenue interest rate			7.50%
Minimum amount of annual net sales to qualify for reduced revenue interest rate by December 31, 2021			$ 350,000,000.0
Maximum amount of US net sales to qualify for the Covered Territory expansion to include worldwide sales by December 31, 2021			$ 350,000,000
Percentage of invested capital received by December 31, 2024, to qualify for second reduced revenue interest rate			100.00%
Revenue interest rate if annual net sales equal or exceed the Sales Threshold and if the Purchasers receive 100% of their invested capital by December 31, 2024			0.40%
Percentage of revenue interests payment on which agreement terminates			195.00%
Percentage of revenue interests payment on which agreement terminates, if prior to the anniversary of the closing date, if put option is exercised			120.00%
Percentage of revenue interests payment on which agreement terminates, prior to the third anniversary of the closing date, if put option is exercised			175.00%
Percentage of revenue interests payment on which agreement terminates, after the third anniversary of the closing date, if put option is exercised			195.00%
Capitalized issuance costs			$ 600,000
Repayment amount expected to pay in next twelve months					14,000,000		$ 14,000,000
Effective annual imputed interest rate (as a percent)							17.20%
Consecutive number of months sales must be at or above milestone amount			6 months
Percentage of increase in royalty rate upon drawdown of third payment			33.33%
Oberland | Revenue Interest Purchase Agreement (RIPA) | Net Sales Less Than $250 Million
Liability Related to the Revenue Interest Purchase Agreement
Initial revenue interest rate			10.00%
Minimum amount of annual net sales to qualify for reduced revenue interest rate by December 31, 2021			$ 250,000,000
Hypothetical sales generated amount			100,000,000
Hypothetical repayment obligation			$ 10,000,000
Oberland | Revenue Interest Purchase Agreement (RIPA) | Net Sales Greater Than $250 Million But Less Than $350 Million
Liability Related to the Revenue Interest Purchase Agreement
Revenue interest rate which will take effect if annual net sales equals or exceeds the sales threshold by December 31, 2021			3.30%
Minimum amount of annual net sales to qualify for reduced revenue interest rate by December 31, 2021			$ 250,000,000
Hypothetical sales generated amount			100,000,000
Hypothetical repayment obligation			3,300,000
Oberland | Revenue Interest Purchase Agreement (RIPA) | Net Sales Greater Than $350 Million
Liability Related to the Revenue Interest Purchase Agreement
Minimum amount of annual net sales to qualify for reduced revenue interest rate by December 31, 2021			350,000,000
Hypothetical sales generated amount			100,000,000
Hypothetical repayment obligation			$ 3,300,000
Oberland | RIPA Amendment
Liability Related to the Revenue Interest Purchase Agreement
Proceeds from Revenue Interest Purchase Agreement		$ 50,000,000
Revenue interest rate which will take effect if annual net sales equals or exceeds the sales threshold by December 31, 2021		3.33%
Initial revenue interest rate		10.00%
Percentage of invested capital received by December 31, 2024, to qualify for second reduced revenue interest rate		100.00%
Percentage of revenue interests payment on which agreement terminates, prior to the third anniversary of the closing date, if put option is exercised		200.00%	200.00%
Percentage of revenue interests payment on which agreement terminates, after the third anniversary of the closing date, if put option is exercised		225.00%
Minimum amount of annual net sales to qualify for reduced revenue interest rate by December 31, 2024, contingent on 100% invested capital received		$ 350,000,000
Percentage of revenue interest payments to qualify for third payment applicable percentage		100.00%
Percentage of cumulative purchaser payments		100.00%
Oberland | RIPA Amendment To The Security Agreement And Waiver
Liability Related to the Revenue Interest Purchase Agreement
Specified net revenue	$ 15,000,000
Deposit to a block account					$ 50,000,000		$ 50,000,000
Company deposit value in blocked account	$ 50,000,000