Treasury Stock - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended					12 Months Ended			150 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Jul. 26, 2006	Sep. 17, 2001	Mar. 31, 2014 Open market stock repurchase program	Mar. 31, 2013 Open market stock repurchase program	Mar. 31, 2012 Open market stock repurchase program	Mar. 31, 2014 Open market stock repurchase program	Mar. 31, 2014 Restricted stock units	Mar. 31, 2013 Restricted stock units	Mar. 31, 2012 Restricted stock units
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program				4,000,000	1,000,000
Additional stock authorized to repurchase under stock repurchase program				3,000,000
Shares repurchased during the period, shares						1,000,407	999,499	1,270,000	3,756,700	216,198	169,531	216,882
Shares repurchased during the period, value	$ 34,322	$ 27,448	$ 20,595			$ 28,800	$ 23,500	$ 16,200		$ 5,500	$ 3,900	$ 4,400