License and Other Agreements - Catalent Agreement for Rimegepant (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Feb. 27, 2020
License and other agreements
Required milestone payments capitalized to intangible asset				$ 41,500
Collaborative arrangement | Catalent Agreement
License and other agreements
Last patent right expiration period (in years)	10 years
Automatic extension period (in years)	1 year
Milestone payments		$ 750	$ 750
Maximum | Collaborative arrangement | Catalent Agreement
License and other agreements
Payment required due to achievement of milestone					$ 1,500
Required milestone payments capitalized to intangible asset			$ 1,500