Computation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Basic Net Income Per Share
Net income	$ 15,432	$ 10,555	$ 37,217	$ 27,149
Weighted average shares used in computing basic net income per share	43,431	42,427	43,125	42,118
Net income per share - basic	$ 0.36	$ 0.25	$ 0.86	$ 0.64
Diluted Net Income Per Share
Net income	$ 15,432	$ 10,555	$ 37,217	$ 27,149
Weighted average shares used in computing basic net income per share	43,431	42,427	43,125	42,118
Effect of dilutive securities	1,339	2,522	1,472	2,687
Weighted average shares used in computing diluted net income per share	44,770	44,949	44,597	44,805
Net income per share - diluted	$ 0.34	$ 0.23	$ 0.83	$ 0.61