Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Aug. 31, 2021	May 31, 2021
Condensed 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	45,300,786
Treasury stock, shares	9,829,628	9,925,551
Accounts receivable, allowances	$ 16.9	$ 16.4
Property, plant and equipment, accumulated depreciation	$ 270.2	$ 260.2