DERIVATIVES - Cumulative Basis Adjustment (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Derivatives
Hedged Asset, Statement of Financial Position [Extensible Enumeration]	Available-for-sale debt securities (including $2,579 and $11,868 pledged to creditors as of September 30, 2024 and December 31, 2023, respectively), Loans, net of unearned income	Available-for-sale debt securities (including $2,579 and $11,868 pledged to creditors as of September 30, 2024 and December 31, 2023, respectively), Loans, net of unearned income
Debt securities AFS, carrying amount of hedged asset/liability	$ 91,697	$ 111,886
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	277	(925)
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, de-designated	$ (68)	$ (282)
Hedged Liability, Statement of Financial Position [Extensible Enumeration]	Long-term debt (including $117,286 and $116,338 as of September 30, 2024 and December 31, 2023, respectively, at fair value)	Long-term debt (including $117,286 and $116,338 as of September 30, 2024 and December 31, 2023, respectively, at fair value)
Long-term debt, carrying amount of hedged asset/liability	$ 151,843	$ 141,449
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, active	237	(908)
Long-term debt, cumulative fair value hedging adjustment included in the carrying amount, de-designated	(4,254)	(5,160)
Physical commodities inventories	7,000	8,000
Physical commodities inventories, cumulative basis adjustments	(200)	1,200
Cumulative basis adjustment within active hedges	299	248
Cumulative basis adjustment within de-designated hedges	86	(51)
Amount of designated hedged items	11,000	14,000
Amortized cost basis of closed portfolios used in hedging relations	30,000	28,000
Unallocated portfolio layer cumulative basis adjustments	299	93
Consumer loans
Derivatives
Debt securities AFS, carrying amount of hedged asset/liability	55,483
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	670
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	55,000	5,000
Unallocated portfolio layer cumulative basis adjustments	670
Corporate loans
Derivatives
Debt securities AFS, carrying amount of hedged asset/liability	5,520	4,968
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, active	65	93
Debt securities AFS, cumulative fair value hedging adjustment included in the carrying amount, de-designated	62	(3)
Amount of designated hedged items	3,700
Amortized cost basis of closed portfolios used in hedging relations	5,500
Unallocated portfolio layer cumulative basis adjustments	$ 65	$ 93