Computation of Basic and Diluted Net Income Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Basic Net Income Per Share
Net income	$ 12,684	$ 4,393	$ 14,814	$ 3,729
Weighted average shares used in computing basic net income per share	40,856	39,592	40,456	39,179
Net income per share - basic	$ 0.31	$ 0.11	$ 0.37	$ 0.10
Diluted Net Income Per Share
Net income	$ 12,684	$ 4,393	$ 14,814	$ 3,729
Weighted average shares used in computing basic net income per share	40,856	39,592	40,456	39,179
Effect of dilutive securities	2,028	2,134	1,889	2,136
Weighted average shares used in computing diluted net income per share	42,884	41,726	42,345	41,315
Net income per share - diluted	$ 0.30	$ 0.11	$ 0.35	$ 0.09