Stock-Based Compensation - Stock Option Activity under All Plans and Other Grants (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding, Beginning Balance	1,231,498	759,577	674,911
Number of Shares, Granted	158,000	551,000	184,000
Number of Shares, Exercised	(130,548)	(46,411)	(37,500)
Number of Shares, Canceled or expired	(407,785)	(32,668)	(61,834)
Number of Shares, Outstanding, Ending Balance	851,165	1,231,498	759,577	674,911
Number of Shares, Options exercisable at March 31, 2014	389,832
Number of Shares, Unvested options expected to become exercisable after March 31, 2014	461,333
Number of Shares, Shares available for future option grants at March 31, 2014	558,113
Aggregate Intrinsic Value, Outstanding, Beginning Balance	$ 720	$ 800	$ 934
Aggregate Intrinsic Value, Exercised	253	35	78
Aggregate Intrinsic Value, Outstanding, Ending Balance	1,516	720	800	934
Aggregate Intrinsic Value, Options exercisable at March 31, 2014	779
Aggregate Intrinsic Value, Unvested options expected to become exercisable after March 31, 2014	$ 737
Approximate Remaining Contractual Term, Outstanding	8 years	7 years	7 years	6 years
Approximate Remaining Contractual Term, Granted	10 years	10 years	10 years
Approximate Remaining Contractual Term, Options exercisable at March 31, 2014	7 years
Approximate Remaining Contractual Term, Unvested options expected to become exercisable after March 31, 2014	9 years
Weighted-Average Exercise Price Outstanding, Beginning Balance	$ 8.20	$ 8.17	$ 8.03
Weighted-Average Exercise Price, Granted	$ 8.58	$ 8.07	$ 8.64
Weighted-Average Exercise Price, Exercised	$ 6.98	$ 6.07	$ 7.36
Weighted-Average Exercise Price, Canceled or expired	$ 8.84	$ 8.51	$ 8.54
Weighted-Average Exercise Price, Outstanding, Ending Balance	$ 8.15	$ 8.20	$ 8.17	$ 8.03
Weighted-Average Exercise Price, Options exercisable at March 31, 2014	$ 7.99
Weighted-Average Exercise Price, Unvested options expected to become exercisable after March 31, 2014	$ 8.28