Revision of Prior Period Financial Statements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		48 Months Ended	51 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Mar. 31, 2020	Jul. 01, 2020	Jan. 01, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Royalty obligation	$ 13,340			$ 21,105	$ 55,426	$ 63,871
Increase to accumulated deficit	$ 1,046,667	$ 1,056,369			$ 1,046,667		$ 1,015,201
Revision of Prior Period, Error Correction, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Governmental rebates		(2,800)					$ (6,300)	$ (6,300)
Royalty obligation		200	$ 200
Increase to accumulated deficit		$ 5,216							$ 5,200	$ 5,100
Revision of Prior Period, Error Correction, Adjustment | Revision Period One
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Governmental rebates			1,800
Revision of Prior Period, Error Correction, Adjustment | Revision Period Two
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Governmental rebates			$ (2,800)