Derivative Instruments and Hedging Activities - Effects of Fair Value and Cash Flow Hedge Accounting (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest income:
Investment Securities	$ 2,550	$ 1,884	$ 1,446
Loans, Including Loans Held for Sale	37,410	28,910	24,263
Other	1,978	443	60
Interest-bearing Deposits	(9,489)	(2,535)	(956)
Securitized Debt Obligations	(959)	(384)	(119)
Senior and Subordinated Notes	(2,204)	(1,074)	(488)
Non-interest income (loss)	1,120	914	824
Amortization expense (benefit)	(79)	(78)	(39)
Non-Interest Income, Other
Interest income:
Realized losses (gains) on foreign exchange contracts reclassified from AOCI	(66)	(17)	163
Fair value hedges \| Investment Securities
Interest income:
Net income (expense) recognized on fair value hedges	81	(42)	(184)
Fair value hedges \| Loans, Including Loans Held for Sale
Interest income:
Net income (expense) recognized on fair value hedges	0	0	0
Fair value hedges \| Other
Interest income:
Net income (expense) recognized on fair value hedges	0	0	0
Fair value hedges \| Interest-bearing Deposits
Interest income:
Net income (expense) recognized on fair value hedges	(388)	6	125
Fair value hedges \| Securitized Debt Obligations
Interest income:
Net income (expense) recognized on fair value hedges	(415)	(47)	106
Fair value hedges \| Senior and Subordinated Notes
Interest income:
Net income (expense) recognized on fair value hedges	(881)	(34)	348
Fair value hedges \| Non-Interest Income, Other
Interest income:
Net income (expense) recognized on fair value hedges	0	(1)	0
Fair value hedges \| Interest rate contracts: \| Investment Securities
Interest income:
Interest recognized on derivatives	158	48	(92)
Gains (losses) recognized on derivatives	(149)	276	207
Gains (losses) recognized on hedged items	72	(366)	(299)
Excluded component of fair value hedges	0	0	0
Fair value hedges \| Interest rate contracts: \| Loans, Including Loans Held for Sale
Interest income:
Interest recognized on derivatives	0	0	0
Gains (losses) recognized on derivatives	0	0	0
Gains (losses) recognized on hedged items	0	0	0
Excluded component of fair value hedges	0	0	0
Fair value hedges \| Interest rate contracts: \| Other
Interest income:
Interest recognized on derivatives	0	0	0
Gains (losses) recognized on derivatives	0	0	0
Gains (losses) recognized on hedged items	0	0	0
Excluded component of fair value hedges	0	0	0
Fair value hedges \| Interest rate contracts: \| Interest-bearing Deposits
Interest income:
Interest recognized on derivatives	(385)	2	126
Gains (losses) recognized on derivatives	220	(542)	(168)
Gains (losses) recognized on hedged items	(223)	546	167
Excluded component of fair value hedges	0	0	0
Fair value hedges \| Interest rate contracts: \| Securitized Debt Obligations
Interest income:
Interest recognized on derivatives	(414)	(48)	123
Gains (losses) recognized on derivatives	244	(698)	(237)
Gains (losses) recognized on hedged items	(245)	699	220
Excluded component of fair value hedges	0	0	0
Fair value hedges \| Interest rate contracts: \| Senior and Subordinated Notes
Interest income:
Interest recognized on derivatives	(1,036)	(197)	209
Gains (losses) recognized on derivatives	733	(1,893)	(799)
Gains (losses) recognized on hedged items	(575)	2,059	941
Excluded component of fair value hedges	(3)	(3)	(3)
Fair value hedges \| Interest rate contracts: \| Non-Interest Income, Other
Interest income:
Interest recognized on derivatives	0	0	0
Gains (losses) recognized on derivatives	42	(84)	(106)
Gains (losses) recognized on hedged items	(42)	83	106
Excluded component of fair value hedges	0	0	0
Cash flow hedges \| Investment Securities
Interest income:
Net income (expense) recognized on cash flow hedges	0	0	38
Cash flow hedges \| Loans, Including Loans Held for Sale
Interest income:
Net income (expense) recognized on cash flow hedges	(1,205)	(121)	919
Cash flow hedges \| Other
Interest income:
Net income (expense) recognized on cash flow hedges	11	3	1
Cash flow hedges \| Interest-bearing Deposits
Interest income:
Net income (expense) recognized on cash flow hedges	0	0	0
Cash flow hedges \| Securitized Debt Obligations
Interest income:
Net income (expense) recognized on cash flow hedges	0	0	0
Cash flow hedges \| Senior and Subordinated Notes
Interest income:
Net income (expense) recognized on cash flow hedges	0	0	0
Cash flow hedges \| Non-Interest Income, Other
Interest income:
Net income (expense) recognized on cash flow hedges	0	(1)	1
Cash flow hedges \| Interest rate contracts: \| Investment Securities
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	38
Cash flow hedges \| Interest rate contracts: \| Loans, Including Loans Held for Sale
Interest income:
Realized gains (losses) reclassified from AOCI into net income	(1,205)	(121)	919
Cash flow hedges \| Interest rate contracts: \| Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Interest rate contracts: \| Interest-bearing Deposits
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Interest rate contracts: \| Securitized Debt Obligations
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Interest rate contracts: \| Senior and Subordinated Notes
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Interest rate contracts: \| Non-Interest Income, Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Foreign exchange and other contracts \| Investment Securities
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Foreign exchange and other contracts \| Loans, Including Loans Held for Sale
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Foreign exchange and other contracts \| Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	11	3	1
Cash flow hedges \| Foreign exchange and other contracts \| Interest-bearing Deposits
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Foreign exchange and other contracts \| Securitized Debt Obligations
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Foreign exchange and other contracts \| Senior and Subordinated Notes
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0	0
Cash flow hedges \| Foreign exchange and other contracts \| Non-Interest Income, Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	$ 0	$ (1)	$ 1

Amortization of Basis Adjustment on Discontinued Hedges

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The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

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