Condensed Consolidated Statement of Shareholders' Equity - 3 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Shares	Additional Paid in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Cowen and Company, LLC Private Placement	Cowen and Company, LLC Private Placement Common Shares	Cowen and Company, LLC Private Placement Additional Paid in Capital	Roivant Sciences, Ltd. Private Placement	Roivant Sciences, Ltd. Private Placement Common Shares	Roivant Sciences, Ltd. Private Placement Additional Paid in Capital
Beginning balance (in shares) at Mar. 31, 2018	60,997,856	60,997,856
Beginning balance at Mar. 31, 2018	$ 37,729	$ 1	$ 266,178	$ 24	$ (228,474)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares (in shares)							2,767,129			1,110,015
Issuance of common shares						$ 57,315	$ 0	$ 57,315	$ 22,500	$ 0	$ 22,500
Share-based compensation expense (in shares)		0
Share-based compensation expense	4,053	$ 0	4,053
Capital contribution — share-based compensation	191		191
Foreign currency translation adjustment	$ 425			425
Issuance of common shares upon exercise of stock options (in shares)	16,218	16,218
Issuance of common shares upon exercise of stock options	$ 76		76
Net loss	$ (62,134)				(62,134)
Ending balance (in shares) at Jun. 30, 2018	64,891,218	64,891,218
Ending balance at Jun. 30, 2018	$ 60,155	$ 1	$ 350,313	$ 449	$ (290,608)