Variable Interest Entities - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 USD ($) collateralized_loan_obligation loan	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Variable interest entities
Number of CLOs | collateralized_loan_obligation	5
Number of SASBs | loan	1
VIE assets	$ 66,169,669,000	$ 69,504,196,000
VIE liabilities	59,129,488,000	62,481,214,000
Temporary equity	415,485,000	414,348,000	$ 364,418,000	$ 362,790,000
Investments in unconsolidated entities	$ 96,927,000	$ 90,376,000
CMBS JV
Variable interest entities
Ownership percentage	51.00%
Primary Beneficiary
Variable interest entities
VIE assets	$ 48,000,000
VIE liabilities	10,200,000
Primary Beneficiary | CMBS Venture Holdings
Variable interest entities
VIE assets	303,100,000
VIE liabilities	66,900,000
Primary Beneficiary | SPT Dolphin
Variable interest entities
VIE assets	2,000,000,000
VIE liabilities	0
Primary Beneficiary | Woodstar Feeder Fund, L.P.
Variable interest entities
VIE assets	600,000,000
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	19,500,000
Not primary beneficiary | Measurement Period Adjustments
Variable interest entities
Investments in unconsolidated entities	800,000
Not primary beneficiary | Securitization SPEs
Variable interest entities
Long term debt, gross	$ 3,900,000,000