Income Taxes - Components of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Current Provision:
Federal	$ (269)	$ 0	$ 0
State	32	89	18
Foreign	1,742	870	333
Total current provision	1,505	959	351
Deferred Provision:
Federal	(568)	0	0
State	0	0	0
Foreign	(240)	0	(87)
Total deferred provision	(808)	0	(87)
Total income tax provision	$ 697	$ 959	$ 264