License Agreement - Narrative (Details) - USD ($) $ in Thousands		2 Months Ended	12 Months Ended
	Apr. 29, 2016	Mar. 31, 2016	Mar. 31, 2017
Other Liabilities Disclosure [Abstract]
Shares issued to Takeda under the Takeda license agreement (in shares)	5,077,001
Period for which royalties are required to be paid after the first commercial sale of relugolix or MVT-602 products			10 years
Ownership percentage to which the warrants entitle Takeda			12.00%
Purchase of in-process research and development expense	$ 13,100	$ 0	$ 13,117
Research and development expense, fair value of shares issued	7,700		$ 7,740
Warrant liability	$ 5,400