Treasury Stock - Schedule of repurchase of common stock (Details) - USD ($) $ in Millions	3 Months Ended						7 Months Ended	9 Months Ended
	Feb. 29, 2024	Nov. 30, 2023	Aug. 31, 2023	Feb. 28, 2023	Nov. 30, 2022	Aug. 31, 2022	Feb. 29, 2024	Feb. 29, 2024	Dec. 13, 2023	Jul. 19, 2023
Equity, Class of Treasury Stock [Line Items]
Authorized amount of stock to be repurchased	$ 166.2						$ 166.2	$ 166.2
Less repurchases made under these authorizations	(54.2)	$ (52.3)	$ (36.2)	$ (46.9)	$ (26.0)	$ (5.1)		(142.7)
Remaining Board authorization at February 29, 2024	46.0						46.0	46.0
Board Authorized 2023 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Authorized amount of stock to be repurchased										$ 100.0
Board Authorized 2024 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Authorized amount of stock to be repurchased	$ 66.2						66.2	$ 66.2	$ 66.2
Under all Board Authorizations
Equity, Class of Treasury Stock [Line Items]
Less repurchases made under these authorizations							$ (120.2)