Stock-Based Compensation - Stock Option Activity under All Plans and Other Grants (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2015		Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding, Beginning Balance		851,165		1,231,498	759,577
Number of Shares, Granted	158,000	440,000		158,000	551,000
Number of Shares, Exercised		(88,833)		(130,548)	(46,411)
Number of Shares, Canceled or expired		(46,333)		(407,785)	(32,668)
Number of Shares, Outstanding, Ending Balance	851,165	1,155,999		851,165	1,231,498	759,577
Number of Shares, Options exercisable at March 31, 2015		597,000
Number of Shares, Unvested options expected to become exercisable after March 31, 2015		558,999
Number of Shares, Shares available for future option grants at March 31, 2015		281,376	[1]
Aggregate Intrinsic Value, Outstanding, Beginning Balance		$ 1,516		$ 720	$ 800
Aggregate Intrinsic Value, Exercised		339		253	35
Aggregate Intrinsic Value, Outstanding, Ending Balance	1,516	1,480		1,516	720	800
Aggregate Intrinsic Value, Options exercisable at March 31, 2015		1,143
Aggregate Intrinsic Value, Unvested options expected to become exercisable after March 31, 2015		$ 391
Approximate Remaining Contractual Term, Outstanding		8 years		8 years	7 years	7 years
Approximate Remaining Contractual Term, Granted		10 years		10 years	10 years
Approximate Remaining Contractual Term, Options exercisable at March 31, 2015		7 years
Approximate Remaining Contractual Term, Unvested options expected to become exercisable after March 31, 2015		9 years
Weighted-Average Exercise Price Outstanding, Beginning Balance		$ 8.15		$ 8.20	$ 8.17
Weighted-Average Exercise Price, Granted	$ 8.58	$ 11.45		$ 8.58	$ 8.07
Weighted-Average Exercise Price, Exercised		$ 7.46		$ 6.98	$ 6.07
Weighted-Average Exercise Price, Canceled or expired		$ 8.20		$ 8.84	$ 8.51
Weighted-Average Exercise Price, Outstanding, Ending Balance	$ 8.15	$ 9.26		$ 8.15	$ 8.20	$ 8.17
Weighted-Average Exercise Price, Options exercisable at March 31, 2015		$ 8.60
Weighted-Average Exercise Price, Unvested options expected to become exercisable after March 31, 2015		$ 10.23

[1] May be decreased by restricted stock grants.