SECURITIES - Summary of Residential Securities and CMBS (Details) $ in Thousands	6 Months Ended
Jun. 30, 2023 USD ($)
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2023	$ 65,789,907
Purchases	21,234,811
Sales	(13,816,489)
Principal paydowns	(3,012,500)
(Amortization) / accretion	(89,009)
Fair value adjustment	1,095,741
Ending balance June 30, 2023	71,202,461
Agency Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2023	62,274,895
Purchases	20,646,908
Sales	(13,221,595)
Principal paydowns	(2,834,559)
(Amortization) / accretion	(100,881)
Fair value adjustment	999,496
Ending balance June 30, 2023	67,764,264
Residential Credit Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2023	2,988,703
Purchases	563,963
Sales	(405,028)
Principal paydowns	(173,160)
(Amortization) / accretion	11,242
Fair value adjustment	86,787
Ending balance June 30, 2023	3,072,507
Commercial Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2023	526,309
Purchases	23,940
Sales	(189,866)
Principal paydowns	(4,781)
(Amortization) / accretion	630
Fair value adjustment	9,458
Ending balance June 30, 2023	$ 365,690

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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