Schedule of Earnings Per Share (Detail)	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Weighted Average Number Of Shares Outstanding Diluted Disclosure Items [Abstract]
Weighted-Average Shares of Common Stock Outstanding	49,604,249	49,090,750	46,622,646
Assumed Exercise of Outstanding Dilutive Options	1,350,556	1,574,491	1,984,563
Less Shares Repurchased from Proceeds of Assumed Exercised Options	(868,636)	(1,032,359)	(1,568,604)
Restricted Stock Units	286,074	306,283	301,845
Weighted-Average Common Stock and Dilutive Securities Outstanding	50,372,243	49,939,165	47,340,450