Summary of Significant Accounting Policies (Details) $ in Thousands		3 Months Ended		12 Months Ended
	May 08, 2019	Jun. 30, 2020 USD ($) shares	Jun. 30, 2019 USD ($) shares	Mar. 31, 2020 USD ($) shares	Feb. 29, 2020 shares	Apr. 01, 2019 USD ($)	Mar. 31, 2019 shares	Mar. 30, 2019 shares
Net Loss per Common Share
Common shares issued (in shares) | shares		40,973,380		40,973,380			22,800,000	182,200,000
Common shares outstanding (in shares) | shares		39,526,299		39,526,299			22,800,000	182,200,000
Reverse share split ratio	0.125
Cash and cash equivalents		$ 55,482		$ 80,752
Accumulated deficit		(767,238)		(758,644)
Net loss		(8,594)	$ (28,057)	(72,600)
Number of options outstanding (in shares) | shares							1,900,000
Operating lease right-of-use assets		1,105		$ 1,532
Lease liability		$ 535
Public Offering
Net Loss per Common Share
Number of securities called by warrants (in shares) | shares					3,301,998
Restricted Stock Units (RSUs)
Net Loss per Common Share
RSUs outstanding (in shares) | shares		800,000
Stock Options | 2015 Equity Incentive Plan
Net Loss per Common Share
Number of options outstanding (in shares) | shares		2,300,000
Accounting Standards Update 2016-02
Net Loss per Common Share
Operating lease right-of-use assets						$ 3,000
Lease liability						2,400
Prepaid rent						$ 600
Money Market Funds
Net Loss per Common Share
Money market funds		$ 40,450
Money Market Funds | Fair Value, Inputs, Level 1
Net Loss per Common Share
Money market funds		$ 40,450
Stock Options
Net Loss per Common Share
Anti-dilutive securities not included in calculation of common shares outstanding (in shares) | shares			3,000,000.0