Stock Based Compensation (Summary Of Restricted Share Activity) (Details) - Restricted Shares	9 Months Ended
	Feb. 29, 2020 $ / shares shares
Number of Shares
Number of Shares, Outstanding, Beginning Balance (in shares) | shares	248,412
Number of Shares, Granted (in shares) | shares	104,566
Number of Shares, Vested (in shares) | shares	(77,801)
Number of Shares, Forfeited (in shares) | shares	(2,131)
Number of Shares, Outstanding, Ending Balance (in shares) | shares	273,046
Weighted Average Grant Date Fair Value
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	38.25
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	43.00
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share) | $ / shares	43.20
Weighted Average Grant Date Fair Value, Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 41.36