Earnings (Loss) Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019
Earnings Per Share, Basic and Diluted [Abstract]
Net income (loss) attributable to Class A and Common Shares	$ 35.1	$ 70.9	$ (4.7)	$ 12.5
Weighted average Shares of Class A Stock and Common Stock outstanding for basic earnings (loss) per share	34.3	34.8	34.3	34.8
Earnings (loss) per share of Class A Stock and Common Stock:
Basic (in Dollars per share)	$ 1.02	$ 2.04	$ (0.14)	$ 0.36
Diluted (in Dollars per share)	$ 1.02	$ 2.02	$ (0.14)	$ 0.35
Weighted Average Number Diluted Shares Outstanding Adjustment	0.1	0.3		0.4
Weighted Average Number of Shares Outstanding, Diluted	34.4	35.1	34.3	35.2