Borrowings - Outstanding Loans Payable of Consolidated Funds (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Borrowing Outstanding	$ 5,516.9	$ 5,890.0
Fair value of liabilities	5,333.2	5,811.7
Senior secured notes
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of liabilities	160.5
Loans Payable of Consolidated Funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Borrowing Outstanding	5,613.5	5,903.0
Fair Value	5,303.7	5,811.0
Senior secured notes
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Borrowing Outstanding	5,466.6	5,585.4
Fair Value	$ 5,085.8	$ 5,561.1
Weighted Average Interest Rate	2.62%	1.68%
Weighted Average Remaining Maturity in Years	9 years 9 months 7 days	10 years 3 months
Subordinated notes, preferred shares and other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Borrowing Outstanding	$ 146.9	$ 317.6
Fair Value	$ 217.9	$ 249.9
Weighted Average Remaining Maturity in Years	9 years 11 months 19 days	10 years 4 months 28 days