Computation of Net Loss per Common Share - Reconciliation of Numerators and Denominators of EPS Calculation (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Numerator:
Net loss	$ (10,355)	$ (9,121)
Denominator:
Weighted-average shares of common stock outstanding (in shares)	14,132	12,312
Weighted-average shares subject to repurchase (in shares)	(456)	(201)
Shares used in per-share calculation ― basic (in shares)	13,676	12,111
Shares used in per-share calculation ― diluted (in shares)	13,676	12,111
Net loss per share ― basic (in dollars per share)	$ (0.76)	$ (0.75)
Net loss per share ― diluted (in dollars per share)	$ (0.76)	$ (0.75)