Development and Commercialization Agreement with Richter (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020	Mar. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Upfront payment received included in current deferred revenue						$ 40,000,000.0
Maximum payment from regulatory milestones achieved							$ 40,000,000.0
Maximum payment from sales-related milestones achieved							$ 107,500,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining transaction price						50,000,000.0
Deferred revenue				$ (23,333,000)	$ 0
Contract assets		$ 0		0		0
Receivables		0		0		$ 0
Decrease in contract liability from regulatory milestones achieved		0	$ 0	33,333,000	$ 0
Increase in contract liability from regulatory milestones achieved	$ 10,000,000.0			10,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining transaction price		$ 16,700,000		$ 16,700,000
Recognition period for remaining transaction price		6 months		6 months