Commitments and Contingencies (Details) - USD ($) $ in Millions		9 Months Ended
	Apr. 07, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Investment commitments		$ 3,100.0		$ 3,000.0
Interest paid on senior notes and other borrowings		65.0	$ 75.8
Credit Agreement
Line of Credit Facility [Line Items]
Credit facility term	5 years
Maximum borrowing capacity	$ 925.0
Optional increased capacity	1,300.0
Secured Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	425.0	425.0
Revolving credit agreement borrowings		311.8
Remaining capacity		113.2
Unsecured Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 500.0
Secured Letters of Credit | Subsidiaries
Line of Credit Facility [Line Items]
Revolving credit agreement borrowings		22.7
Unsecured Letters of Credit | Subsidiaries
Line of Credit Facility [Line Items]
Revolving credit agreement borrowings		$ 290.0