Investment Securities - Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities	$ 91,941	$ 93,806
Credit loss allowance	23,490	24,463
HTM debt securities	393,909	431,424
Total investment securities	497,459	533,258
VIE eliminations
Debt Securities, Available-for-sale [Line Items]
Equity security	(1,539,976)	(1,618,801)
CMBS
Debt Securities, Available-for-sale [Line Items]
Credit loss allowance	11	85
HTM debt securities	309,817	357,012
Before consolidation of securitization VIEs
Debt Securities, Available-for-sale [Line Items]
HTM debt securities	370,419	406,961
Equity security, fair value	3,800	5,146
Total investment securities	2,037,435	2,152,059
Before consolidation of securitization VIEs | RMBS
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities	91,941	93,806
Equity security	422,297	421,122
Before consolidation of securitization VIEs | CMBS
Debt Securities, Available-for-sale [Line Items]
Equity security	1,148,978	1,225,024
Marketable Securities, Non-Controlling Interest	$ 141,100	$ 148,600