Investment Securities - Purchases, Sales and Redemptions, and Principal Collections for All Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	$ 112,576	$ 7,747	$ 135,309	$ 21,573
Sales and redemptions	9,111	4,193	9,736	5,543
Principal collections	2,821	1,985	7,652	54,952
Redemptions	0		0
Securitization VIEs
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	(44,454)	(56,999)	(44,454)	(61,638)
Sales and redemptions	(4,200)	0	(8,065)	0
Principal collections	(12,539)	(13,109)	(63,825)	(85,229)
Redemptions	(82,082)		(82,082)
HTM Securities
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	110,239	7,747	126,445	17,546
Sales and redemptions	0	0	0	0
Principal collections	891	118	3,417	50,968
Redemptions	0		0
Equity Security
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	0	0	0	0
Sales and redemptions	0	0	625	1,350
Principal collections	0	0	0	0
Redemptions	0		0
RMBS \| Available-for-sale
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	0	0	0	0
Sales and redemptions	0	0	0	0
Principal collections	1,771	1,825	3,710	3,898
Redemptions	0		0
RMBS \| Fair value option
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	0	0	0	0
Sales and redemptions	0	0	0	0
Principal collections	7,710	10,078	15,885	20,158
Redemptions	82,082		82,082
CMBS \| Fair value option
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings	46,791	56,999	53,318	65,665
Sales and redemptions	13,311	4,193	17,176	4,193
Principal collections	4,988	$ 3,073	48,465	65,157
Redemptions	$ 0		$ 0
CMBS \| Fair value option \| Consolidated Partnership
Debt Securities, Available-for-sale [Line Items]
Purchases/fundings				$ 3,400