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, 2020		103,179,000
Beginning balance at Mar. 31, 2020	$ 190,731	$ 103	$ 625,474	$ (12,176)	$ (422,670)	$ (2,800)	$ (2,800)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under stock plans, less withholding (in shares)		688,000
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		103,867,000
Ending balance at Jun. 30, 2020	178,866	$ 104	657,014	(10,869)	(467,383)
Beginning balance (in shares) at Mar. 31, 2021		109,135,000
Beginning balance at Mar. 31, 2021	160,504	$ 109	755,643	(4,193)	(591,055)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under stock plans, less withholding (in shares)		1,562,000
Issuance of common stock under stock plans, less withholding	3,440	$ 2	3,438
Stock-based compensation expense	36,508		36,508
Unrealized investment gain	(33)			(33)
Foreign currency translation adjustment	283			283
Net loss	(43,906)				(43,906)
Ending balance (in shares) at Jun. 30, 2021		110,697,000
Ending balance at Jun. 30, 2021	$ 156,796	$ 111	$ 795,589	$ (3,943)	$ (634,961)