CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Cumulative effect, period of adoption, adjustment	Cumulative effect, period of adoption, adjustment Accumulated Deficit
Beginning balance (in shares) at Mar. 31, 2019		96,119,888
Beginning balance at Mar. 31, 2019	$ 249,390	$ 96	$ 506,949	$ (7,353)	$ (250,302)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under stock plans, less withholding (in shares)		451,308
Issuance of common stock under stock plans, less withholding	1,494	$ 1	1,493
Stock-based compensation expense	14,059		14,059
Unrealized investment gain	121			121
Foreign currency translation adjustment	(652)			(652)
Net loss	(34,265)				(34,265)
Ending balance (in shares) at Jun. 30, 2019		96,571,196
Ending balance at Jun. 30, 2019	230,147	$ 97	522,501	(7,884)	(284,567)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment to opening balance for change in accounting principle						$ (2,800)	$ (2,800)
Beginning balance (in shares) at Mar. 31, 2020		103,178,621
Beginning balance at Mar. 31, 2020	190,731	$ 103	625,474	(12,176)	(422,670)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under stock plans, less withholding (in shares)		688,414
Issuance of common stock under stock plans, less withholding	(66)	$ 1	(67)
Stock-based compensation expense	23,118		23,118
Issuance of common stock related to acquisition	8,489		8,489
Unrealized investment gain	422			422
Foreign currency translation adjustment	885			885
Net loss	(41,913)				(41,913)
Ending balance (in shares) at Jun. 30, 2020		103,867,035
Ending balance at Jun. 30, 2020	$ 178,866	$ 104	$ 657,014	$ (10,869)	$ (467,383)