Goodwill and Purchased Intangibles Assets - Schedule of Purchased Intangible Assets Subject to Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 5,300	$ 5,300
Accumulated Amortization	(2,404)	(1,639)
Net Carrying Amount	2,896	3,661
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,900	4,900
Accumulated Amortization	(2,004)	(1,339)
Net Carrying Amount	2,896	3,561
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	100	100
Accumulated Amortization	(100)	(75)
Net Carrying Amount	0	25
Other intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	300	300
Accumulated Amortization	(300)	(225)
Net Carrying Amount	$ 0	$ 75