Employee Benefit Plans - Components of Net Pension (Income)/Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Retirement Benefits [Abstract]
Service cost – benefits earned during the period	$ 1.5	$ 1.3
Interest cost on projected benefits	21.9	21.2
Expected return on plan assets	(29.0)	(29.0)
Net amortization and deferral	0.7	0.7
Net pension (income)/expense	$ (4.9)	$ (5.8)