Shareholders' Equity (Details) (USD $)	0 Months Ended		3 Months Ended	9 Months Ended
	Oct. 07, 2013	Jul. 25, 2013	Feb. 28, 2014	Feb. 28, 2014	Feb. 28, 2013
Stockholders' Equity Note [Abstract]
Stock repurchase program, authorized amount		$ 250,000,000.0
ASR, authorized amount	100,000,000
Shares expected to be repurchased and retired, value	100,000,000
Repurchase of common stock (in shares)	1,600,000.0		154,886	4,961,000
Repurchase of common stock, average price per share	$ 60.96		$ 67.65	$ 52.53
Repurchase of common stock			10,478,000	260,609,000	137,653,000
Remaining authorized repurchase amount				$ 114,041,764