CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Accumulated deficit Impact of adoption of ASC 842	Accumulated deficit	Accumulated other comprehensive loss	Impact of adoption of ASC 842	Total
Balance at Mar. 31, 2019	$ 32	$ 198,645		$ (59,766)	$ (1,055)		$ 137,856
Balance (in shares) at Mar. 31, 2019	31,656,950
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment					(182)		(182)
Unrealized gain (loss) on short-term investments					65		65
Exercise of stock options		18					18
Exercise of stock options (in shares)	6,751
Stock-based compensation expense		1,810					1,810
Impact of adoption of ASC 842			$ 93			$ 93
Net loss				(9,508)			(9,508)
Balance at Jun. 30, 2019	$ 32	200,473		(69,181)	(1,172)		130,152
Balance (in shares) at Jun. 30, 2019	31,663,701
Balance at Mar. 31, 2019	$ 32	198,645		(59,766)	(1,055)		137,856
Balance (in shares) at Mar. 31, 2019	31,656,950
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment							(400)
Unrealized gain (loss) on short-term investments							25
Net loss							(20,647)
Balance at Sep. 30, 2019	$ 32	202,359		(80,320)	(1,430)		120,641
Balance (in shares) at Sep. 30, 2019	31,719,346
Balance at Mar. 31, 2019	$ 32	198,645		(59,766)	(1,055)		137,856
Balance (in shares) at Mar. 31, 2019	31,656,950
Balance at Mar. 31, 2020	$ 37	296,961		(112,298)	(982)		183,718
Balance (in shares) at Mar. 31, 2020	36,668,743
Balance at Jun. 30, 2019	$ 32	200,473		(69,181)	(1,172)		130,152
Balance (in shares) at Jun. 30, 2019	31,663,701
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment					(218)		(218)
Unrealized gain (loss) on short-term investments					(40)		(40)
Exercise of stock options		105					105
Exercise of stock options (in shares)	55,645
Stock-based compensation expense		1,781					1,781
Net loss				(11,139)			(11,139)
Balance at Sep. 30, 2019	$ 32	202,359		(80,320)	(1,430)		120,641
Balance (in shares) at Sep. 30, 2019	31,719,346
Balance at Mar. 31, 2020	$ 37	296,961		(112,298)	(982)		183,718
Balance (in shares) at Mar. 31, 2020	36,668,743
Increase (decrease) in Stockholders' Equity
Issuance of prefunded warrants to purchase common stock, net of $2,100 issuance costs		32,900					32,900
Issuance of common stock, net of issuance costs and underwriter fees of $5,117	$ 3	74,879					74,882
Issuance of common stock, net of issuance costs and underwriter fees of $5,117 (in shares)	3,478,261
Foreign currency translation adjustment					(12)		(12)
Unrealized gain (loss) on short-term investments					(196)		(196)
Exercise of stock options		1,547					1,547
Exercise of stock options (in shares)	133,416
Stock-based compensation expense		2,468					2,468
Net loss				(17,493)			(17,493)
Balance at Jun. 30, 2020	$ 40	408,755		(129,791)	(1,190)		277,814
Balance (in shares) at Jun. 30, 2020	40,280,420
Balance at Mar. 31, 2020	$ 37	296,961		(112,298)	(982)		183,718
Balance (in shares) at Mar. 31, 2020	36,668,743
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment							614
Unrealized gain (loss) on short-term investments							$ (244)
Exercise of stock options (in shares)							165,268
Net loss							$ (37,588)
Balance at Sep. 30, 2020	$ 40	411,847		(149,886)	(611)		261,390
Balance (in shares) at Sep. 30, 2020	40,312,272
Balance at Jun. 30, 2020	$ 40	408,755		(129,791)	(1,190)		277,814
Balance (in shares) at Jun. 30, 2020	40,280,420
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment					626		626
Unrealized gain (loss) on short-term investments					(47)		(47)
Exercise of stock options		291					291
Exercise of stock options (in shares)	31,852
Stock-based compensation expense		2,801					2,801
Net loss				(20,095)			(20,095)
Balance at Sep. 30, 2020	$ 40	$ 411,847		$ (149,886)	$ (611)		$ 261,390
Balance (in shares) at Sep. 30, 2020	40,312,272