SECURITIES - Summary of Residential Securities and CMBS (Details) $ in Thousands	12 Months Ended
Dec. 31, 2022 USD ($)
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2022	$ 63,655,674
Purchases	46,462,100
Sales and transfers	(29,182,033)
Principal paydowns	(9,467,555)
(Amortization) / accretion	(45,650)
Fair value adjustment	(5,632,629)
Ending balance December 31, 2022	65,789,907
Agency Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2022	60,525,605
Purchases	44,470,550
Sales and transfers	(28,360,527)
Principal paydowns	(8,942,437)
(Amortization) / accretion	(53,880)
Fair value adjustment	(5,364,416)
Ending balance December 31, 2022	62,274,895
Residential Credit Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2022	2,599,564
Purchases	1,728,916
Sales and transfers	(573,571)
Principal paydowns	(520,743)
(Amortization) / accretion	7,403
Fair value adjustment	(252,866)
Ending balance December 31, 2022	2,988,703
Commercial mortgage-backed securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2022	530,505
Purchases	262,634
Sales and transfers	(247,935)
Principal paydowns	(4,375)
(Amortization) / accretion	827
Fair value adjustment	(15,347)
Ending balance December 31, 2022	$ 526,309

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Debt Securities, Available-For-Sale [Roll Forward]

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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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