Stock-Based Compensation Plans (Tables)

6 Months Ended

Nov. 30, 2011

Stock-Based Compensation Plans [Abstract]

Schedule Of Weighted-Average Grant Date Fair Value Of Options Granted

		Six months ended November 30,
		2011				2010
Weighted average grant date fair value	$		19.72		$		17.61
Weighted average assumptions used:
Expected volatility			.411				.420
Expected term of the option in years			10				10
Risk-free interest rate			2.97	%			3.33	%
Expected dividend yield			.56	%			.86	%

Schedule Of Stock Option Transactions

	Shares Under Option			Weighted-Average Option Price
Outstanding at May 31, 2011		1,972,441		$	39.58
Granted		16,000			38.40
Exercised		(6,853	)		23.10
Canceled		(49,144	)		39.31
Outstanding at November 30, 2011		1,932,444		$	39.63
Exercisable at November 30, 2011		1,030,584		$	41.39

Schedule Of Stock Options Outstanding Range Of Exercise Prices

	Range of Exercise Prices
	$16.04 - $27.39		$33.57 - $48.60		$50.63 - $70.18
Options outstanding
Shares outstanding		559,878		820,006		552,560
Weighted-average remaining term in years		4.26		7.25		4.47
Weighted-average exercise price	$	22.00	$	39.70	$	57.41
Options exercisable
Shares exercisable		356,058		230,926		443,600
Weighted-average remaining term in years		2.85		4.19		4.29
Weighted-average exercise price	$	20.51	$	42.55	$	57.54