Variable Interest Entities - Narrative (Details)	9 Months Ended
	Sep. 30, 2022 USD ($) collateralized_loan_obligation loan	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Variable interest entities
Number of CLOs | collateralized_loan_obligation	5
Number of SASBs | loan	1
VIE assets	$ 80,002,858,000		$ 83,850,397,000
VIE liabilities	72,837,300,000		77,201,590,000
Temporary equity	344,373,000	$ 322,753,000	214,915,000	$ 0	$ 0	$ 0
Investments in unconsolidated entities	$ 83,164,000		$ 90,097,000
CMBS JV
Variable interest entities
Ownership percentage	51.00%
Primary beneficiary
Variable interest entities
VIE assets	$ 76,600,000
VIE liabilities	34,400,000
Primary beneficiary | CMBS Venture Holdings
Variable interest entities
VIE assets	369,500,000
VIE liabilities	89,000,000
Primary beneficiary | SPT Dolphin
Variable interest entities
VIE assets	1,700,000,000
VIE liabilities	0
Primary beneficiary | Woodstar Feeder Fund, L.P.
Variable interest entities
VIE assets	500,000,000
VIE liabilities	0
Temporary equity	300,000,000
Not primary beneficiary
Variable interest entities
Maximum risk of loss related to VIEs, on fair value basis	20,700,000
Not primary beneficiary | Measurement Period Adjustments
Variable interest entities
Investments in unconsolidated entities	11,900,000
Not primary beneficiary | Securitization SPEs
Variable interest entities
Long term debt, gross	$ 4,700,000,000