Payables and Accrued Expenses - Components of Payables and Accrued Expenses (Details) - USD ($) $ in Millions	Jun. 30, 2022	Jun. 30, 2021
Other Liabilities Disclosure [Abstract]
Accounts payable	$ 244.9	$ 248.9
Employee compensation and benefits	348.1	343.7
Accrued broker fees	154.1	136.0
Accrued dividend payable	75.0	66.8
Business process outsourcing administration fees	65.5	66.1
Customer deposits	58.7	55.5
Accrued taxes	40.9	42.6
Operating lease liabilities - Current	45.4	40.2
Other	82.2	102.9
Total	$ 1,114.9	$ 1,102.7