Investment Securities - Purchases, Sales and Redemptions, and Principal Collections for All Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	$ 13,826	$ 9,220
Sales and redemptions	1,350	1,314
Principal collections	52,967	19,149
Securitization VIEs
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	(4,639)	0
Sales and redemptions	0	(3,166)
Principal collections	(72,120)	(15,022)
HTM Securities
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	9,799	9,220
Sales and redemptions	0	0
Principal collections	50,850	17,163
Equity Security
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	0	0
Sales and redemptions	1,350	1,314
Principal collections	0	0
RMBS | Available-for-sale
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	0	0
Sales and redemptions	0	0
Principal collections	2,073	1,925
RMBS | Fair value option
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	0	0
Sales and redemptions	0	0
Principal collections	10,080	11,883
CMBS | Fair value option
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	8,666	0
Sales and redemptions	0	3,166
Principal collections	62,084	$ 3,200
CMBS | Fair value option | Consolidated Partnership
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	$ 3,400