Variable Interest Entities - Narrative (Details)	3 Months Ended
	Mar. 31, 2023 USD ($) loan collateralized_loan_obligation	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Variable interest entities
Number of CLOs | collateralized_loan_obligation	5
Number of SASBs | loan	1
VIE assets	$ 77,354,380,000	$ 79,043,129,000
VIE liabilities	70,237,489,000	71,844,422,000
Temporary equity	364,418,000	362,790,000	$ 261,685,000	$ 214,915,000
Investments in unconsolidated entities	$ 93,069,000	$ 91,892,000
CMBS JV
Variable interest entities
Ownership percentage	51.00%
Primary beneficiary
Variable interest entities
VIE assets	$ 75,400,000
VIE liabilities	35,300,000
Primary beneficiary | CMBS Venture Holdings
Variable interest entities
VIE assets	360,300,000
VIE liabilities	87,400,000
Primary beneficiary | SPT Dolphin
Variable interest entities
VIE assets	1,800,000,000
VIE liabilities	0
Primary beneficiary | Woodstar Feeder Fund, L.P.
Variable interest entities
VIE assets	500,000,000
VIE liabilities	0
Temporary equity	400,000,000
Not primary beneficiary
Variable interest entities
Maximum risk of loss related to VIEs, on fair value basis	18,900,000
Not primary beneficiary | Measurement Period Adjustments
Variable interest entities
Investments in unconsolidated entities	900,000
Not primary beneficiary | Securitization SPEs
Variable interest entities
Long term debt, gross	$ 4,600,000,000