Stock Based Compensation (Summary Of Restricted Share Activity) (Details) - Restricted Shares	3 Months Ended
	Aug. 31, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares, Outstanding, Beginning Balance (in shares) | shares	248,412
Number of Shares, Granted (in shares) | shares	0
Number of Shares, Vested (in shares) | shares	(1,000)
Number of Shares, Forfeited (in shares) | shares	(851)
Number of Shares, Outstanding, Ending Balance (in shares) | shares	246,561
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 43.20
Weighted Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	0
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	43.30
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share) | $ / shares	43.12
Weighted Average Grant Date Fair Value, Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 43.20