Revenue Components - Disaggregation of Revenue (Details) - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Pfizer collaboration revenue	$ 104,996,000	$ 22,354,000	$ 0
Total revenues	230,972,000	59,317,000	0
ORGOVYX
Disaggregation of Revenue [Line Items]
Revenues	82,959,000	3,630,000	0
MYFEMBREE
Disaggregation of Revenue [Line Items]
Revenues	6,355,000	0	0
Richter product supply and royalties
Disaggregation of Revenue [Line Items]
Revenues	4,995,000	0	0
Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues	94,309,000	3,630,000	0
Amortization of upfront payment
Disaggregation of Revenue [Line Items]
Pfizer collaboration revenue	83,897,000	22,354,000	0
Amortization of regulatory milestone
Disaggregation of Revenue [Line Items]
Pfizer collaboration revenue	21,099,000	0	0
Richter license and milestone revenue
Disaggregation of Revenue [Line Items]
Revenues	$ 31,667,000	$ 33,333,000	$ 0