Repurchase of Common Stock - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended								0 Months Ended
	Oct. 01, 2013	May 31, 2014	May 31, 2014 Prior Periods	May 31, 2014 Common Stock	May 31, 2014 Additional Paid-in Capital	May 31, 2014 Retained Earnings	May 31, 2014 Share Repurchase Plan Common Stock	May 31, 2014 Share Repurchase Plan Additional Paid-in Capital	May 31, 2014 Share Repurchase Plan Retained Earnings	Jun. 23, 2013 Maximum
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 25,000,000									$ 50,000,000
Stock Repurchased and Retired During Period, Shares		369,900	89,569	(459,000)
Stock Repurchased and Retired During Period, Value		13,300,000	1,300,000	138,000	2,232,000	12,308,000
Common stock share purchase, reduction							$ 100,000	$ 2,200,000	$ 12,300,000