Calculation of Earnings Per Share - Additional Information (Details)	3 Months Ended		6 Months Ended
	Nov. 30, 2019 shares	Dec. 01, 2018 shares	Nov. 30, 2019 Number shares
Schedule Of Earning Per Share [Line Items]
Limit of cash dividends Class B common stock (percent)			90.00%
Common stock options anti-dilutive	860,000	117,000	916,000
Common Stock
Schedule Of Earning Per Share [Line Items]
Common stock shares, authorized	17,000,000		17,000,000
Common Class B
Schedule Of Earning Per Share [Line Items]
Common stock shares, authorized	3,000,000		3,000,000
Number of votes per share | Number			10