Employee Benefit Plans - Components of Net Pension (Income)/Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Retirement Benefits [Abstract]
Service cost – benefits earned during the period	$ 1.3	$ 1.2	$ 3.9	$ 3.5
Interest cost on projected benefits	21.2	19.5	63.4	58.6
Expected return on plan assets	(29.0)	(31.9)	(86.9)	(95.6)
Net amortization and deferral	0.7	0.5	2.2	1.4
Settlement charges and special termination benefits	0.0	0.0	0.0	1.4
Net pension (income)/expense	$ (5.8)	$ (10.7)	$ (17.4)	$ (30.7)