DERIVATIVES - Cumulative Basis Adjustment (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Debt securities AFS, carrying amount of hedged asset/liability	$ 90,947	$ 98,837
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	(2,079)	(2,976)
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, de-designated	(320)	(333)
Long-term debt, carrying amount of hedged asset/liability	135,571	144,549
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, active	(2,928)	(5,040)
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, de-designated	(4,493)	(3,399)
Cumulative basis adjustment within active hedges	(1)	(91)
Cumulative basis adjustment within de-designated hedges	(295)	(309)
Amount of designated hedged items	7,000	3,000
Amortized cost basis of closed portfolios used in hedging relations	$ 14,000	$ 11,000