DERIVATIVES - Cumulative Basis Adjustment (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Derivatives
Hedged Asset, Statement of Financial Position [Extensible Enumeration]	Available-for-sale debt securities (including $2,859 and $11,868 pledged to creditors as of June 30, 2024 and December 31, 2023, respectively), Loans, net of unearned income	Available-for-sale debt securities (including $2,859 and $11,868 pledged to creditors as of June 30, 2024 and December 31, 2023, respectively), Loans, net of unearned income
Debt securities AFS, carrying amount of hedged asset/liability	$ 98,577	$ 111,886
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	(1,096)	(925)
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, de-designated	$ (249)	$ (282)
Hedged Liability, Statement of Financial Position [Extensible Enumeration]	Long-term debt (including $109,406 and $116,338 as of June 30, 2024 and December 31, 2023, respectively, at fair value)	Long-term debt (including $109,406 and $116,338 as of June 30, 2024 and December 31, 2023, respectively, at fair value)
Long-term debt, carrying amount of hedged asset/liability	$ 141,883	$ 141,449
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, active	(1,628)	(908)
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, de-designated	(5,153)	(5,160)
Physical commodities inventories	7,000	8,000
Physical commodities inventories, cumulative basis adjustments	(200)	1,200
Cumulative basis adjustment within active hedges	(213)	248
Cumulative basis adjustment within de-designated hedges	(23)	(51)
Amount of designated hedged items	21,000	14,000
Amortized cost basis of closed portfolios used in hedging relations	30,000	28,000
Unallocated portfolio layer cumulative basis adjustments	(213)	93
Consumer loans
Derivatives
Debt securities AFS, carrying amount of hedged asset/liability	55,577
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	(38)
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, de-designated	0
Amount of designated hedged items	14,900	3,600
Amortized cost basis of closed portfolios used in hedging relations	56,000	5,000
Unallocated portfolio layer cumulative basis adjustments	(38)
Corporate loans
Derivatives
Debt securities AFS, carrying amount of hedged asset/liability	5,387	4,968
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	(23)	93
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, de-designated	(29)	(3)
Amount of designated hedged items	3,900
Amortized cost basis of closed portfolios used in hedging relations	5,400
Unallocated portfolio layer cumulative basis adjustments	$ (23)	$ 93