CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	May 31, 2018	May 31, 2017
CONSOLIDATED BALANCE SHEETS
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, authorized shares	250,000	250,000
Preferred stock, issued shares	0	0
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	45,300,786	45,175,302
Treasury stock, shares	10,585,165	10,820,844