Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss		$ (224,076)	$ (198,537)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation		34,178	13,763
Depreciation and amortization	[1]	1,236	298
Amortization of debt discount and issuance costs		1,486	1,378
Loss on extinguishment of debt		4,851	0
Other items		(1,174)	799
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		(1,892)	(7,235)
Income tax receivable		524	233
Other assets		(272)	(146)
Accounts payable		(4,402)	893
Interest payable		(1,077)	147
Interest payable (related party)		16	0
Accrued expenses		(8,400)	18,079
Operating lease liabilities		(547)
Due to former majority shareholder		(121)	(1,894)
Deferred rent		0	724
Deferred interest payable		(2,273)	518
Net cash used in operating activities		(201,943)	(170,980)
Cash flows from investing activities:
Purchases of marketable securities		(32,076)	0
Maturities of marketable securities		16,440	0
Purchases of property and equipment		(824)	(718)
Net cash used in investing activities		(16,460)	(718)
Cash flows from financing activities:
Proceeds from third party debt financings, net of financing costs paid		0	54,000
Proceeds from related party debt financings		113,700	0
Proceeds from stock option exercises		667	771
Payments on third party debt financings and redemption fees		(105,420)	0
Payment of annual debt administration fee to NovaQuest		(300)	(300)
Net cash provided by financing activities		145,651	246,677
Net change in cash, cash equivalents and restricted cash		(72,752)	74,979
Cash, cash equivalents and restricted cash, beginning of period		157,199	108,624
Cash, cash equivalents and restricted cash, end of period		84,447	183,603
Non-cash financing activities:
Offering costs included in accounts payable and accrued expenses		0	18
Deferred financing costs included in accrued expenses		0	26
Stock options exercised receivables, included in prepaid expenses and other current assets		0	(22)
Public Offering
Cash flows from financing activities:
Cash proceeds from issuance of common shares		134,458	74,391
Private Placement | Cowen and Company, LLC
Cash flows from financing activities:
Cash proceeds from issuance of common shares		2,546	57,315
Private Placement | Roivant Sciences, Ltd.
Cash flows from financing activities:
Cash proceeds from issuance of common shares		0	22,500
Private Placement | NovaQuest
Cash flows from financing activities:
Cash proceeds from issuance of common shares		$ 0	$ 38,000

[1] Includes amortization of operating lease right-of-use asset.