Investment Securities - Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities	$ 100,319	$ 102,368
Credit loss allowance	17,589	13,143
HTM debt securities	606,592	619,397
Total investment securities	716,073	735,562
VIE eliminations
Debt Securities, Available-for-sale [Line Items]
Equity security	(1,540,154)	(1,578,859)
CMBS
Debt Securities, Available-for-sale [Line Items]
Credit loss allowance	182	164
HTM debt securities	561,174	580,704
CMBS \| Non- Controlling Interests
Debt Securities, Available-for-sale [Line Items]
Equity security	171,100	177,300
Before consolidation of securitization VIEs
Debt Securities, Available-for-sale [Line Items]
HTM debt securities	589,003	606,254
Equity security, fair value	7,265	8,340
Total investment securities	2,256,227	2,314,421
Before consolidation of securitization VIEs \| RMBS
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities	100,319	102,368
Equity security	434,916	449,909
Before consolidation of securitization VIEs \| CMBS
Debt Securities, Available-for-sale [Line Items]
Equity security	$ 1,124,724	$ 1,147,550

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