Collaborative Arrangement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		16 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Collaboration revenue	$ 1,032	$ 1,069	$ 2,281	$ 1,069
Deferred revenue	11,100		11,100		$ 11,100
Fixed consideration
Disaggregation of Revenue [Line Items]
Performance obligation at inception of arrangement	20,000		20,000		20,000	$ 20,000
Portion of fixed consideration received					17,000
Variable consideration | Achievement of regulatory milestones
Disaggregation of Revenue [Line Items]
Amount that can be earned upon achievement of milestone	66,000		66,000		66,000
Variable consideration | Achievement of net sales milestones
Disaggregation of Revenue [Line Items]
Amount that can be earned upon achievement of net sales milestone	$ 42,500		$ 42,500		$ 42,500