Payables and Accrued Expenses - Components of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Jun. 30, 2021
Payables and Accruals [Abstract]
Accounts payable	$ 197.5	$ 248.9
Employee compensation and benefits	293.2	343.7
Accrued broker fees	101.4	136.0
Accrued dividend payable	74.8	66.8
Business process outsourcing administration fees	71.6	66.1
Customer deposits	66.7	55.5
Operating lease liabilities	40.0	40.2
Accrued taxes	32.6	42.6
Other	87.9	102.9
Total	$ 965.8	$ 1,102.7
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total	Total