Consolidated Balance Sheets (Parentheticals) - $ / shares	May 31, 2020	May 31, 2019
Preferred stock par value (in Dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Treasury stock (in shares)	10,400,000	9,500,000
Common Stock [Member]
Common Stock, par value per share (in Dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	70,000,000	70,000,000
Common Stock, shares issued	42,900,000	42,900,000
Common Stock, shares outstanding	32,529,874	33,400,000
Class A Stock [Member]
Common Stock, par value per share (in Dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	4,000,000	4,000,000
Common Stock, shares issued	1,700,000	1,700,000
Common Stock, shares outstanding	1,656,200	1,700,000