Net Loss Per Share - Computation of Net Loss Per Share, Basic and Diluted (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator:
Net loss	$ (14,691)	$ (14,130)	$ (30,625)	$ (32,201)
Denominator:
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	54,699	51,328	54,201	50,779
Net loss per share-basic and diluted (in usd per share)	$ (0.27)	$ (0.28)	$ (0.57)	$ (0.63)