Schedule of Earnings Per Share Basic And Diluted (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Basic Net Income Per Share
Net income	$ 3,622	$ 4,393	$ 1,059	$ (1,723)	$ 3,742	$ 2,684	$ 5,469	$ 3,119	$ 7,351	$ 15,014	$ 1,495
Weighted average shares used in computing basic net income per share									39,334	39,113	38,374
Net income per share-basic	$ 0.09	$ 0.11	$ 0.03	$ (0.04)	$ 0.10	$ 0.07	$ 0.14	$ 0.08	$ 0.19	$ 0.38	$ 0.04
Diluted Net Income Per Share
Net income	$ 3,622	$ 4,393	$ 1,059	$ (1,723)	$ 3,742	$ 2,684	$ 5,469	$ 3,119	$ 7,351	$ 15,014	$ 1,495
Weighted average shares used in computing basic net income per share									39,334	39,113	38,374
Effect of dilutive securities									2,272	1,939	1,798
Weighted average shares used in computing diluted net income per share									41,606	41,052	40,172
Net income per share-diluted	$ 0.09	$ 0.11	$ 0.03	$ (0.04)	$ 0.09	$ 0.07	$ 0.13	$ 0.08	$ 0.18	$ 0.37	$ 0.04