Derivative Instruments and Hedging Activities - Effects of Fair Value and Cash Flow Hedge Accounting (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Interest income:
Investment Securities	$ 832	$ 770
Loans, Including Loans Held for Sale	14,735	10,157
Other	664	491
Interest-bearing Deposits	(3,387)	(2,715)
Securitized Debt Obligations	(141)	(176)
Senior and Subordinated Notes	(532)	(505)
Non-interest income (expense)	313	255
Amortization expense (benefit)	(20)	(10)
Non-Interest Income, Other
Interest income:
Realized gain (loss) on foreign exchange contracts reclassified from AOCI	76	(126)
Fair value hedges \| Investment Securities
Interest income:
Net income (expense) recognized on fair value hedges	1	14
Fair value hedges \| Loans, Including Loans Held for Sale
Interest income:
Net income (expense) recognized on fair value hedges	0	0
Fair value hedges \| Other
Interest income:
Net income (expense) recognized on fair value hedges	0	0
Fair value hedges \| Interest-bearing Deposits
Interest income:
Net income (expense) recognized on fair value hedges	(9)	(35)
Fair value hedges \| Securitized Debt Obligations
Interest income:
Net income (expense) recognized on fair value hedges	(21)	(50)
Fair value hedges \| Senior and Subordinated Notes
Interest income:
Net income (expense) recognized on fair value hedges	(48)	(120)
Fair value hedges \| Non-Interest Income, Other
Interest income:
Net income (expense) recognized on fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Investment Securities
Interest income:
Interest recognized on derivatives	4	32
Gains (losses) recognized on derivatives	57	(98)
Gains (losses) recognized on hedged items	(60)	80
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Loans, Including Loans Held for Sale
Interest income:
Interest recognized on derivatives	0	0
Gains (losses) recognized on derivatives	0	0
Gains (losses) recognized on hedged items	0	0
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Other
Interest income:
Interest recognized on derivatives	0	0
Gains (losses) recognized on derivatives	0	0
Gains (losses) recognized on hedged items	0	0
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Interest-bearing Deposits
Interest income:
Interest recognized on derivatives	(9)	(35)
Gains (losses) recognized on derivatives	(19)	75
Gains (losses) recognized on hedged items	19	(75)
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Securitized Debt Obligations
Interest income:
Interest recognized on derivatives	(21)	(49)
Gains (losses) recognized on derivatives	(13)	73
Gains (losses) recognized on hedged items	13	(74)
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Senior and Subordinated Notes
Interest income:
Interest recognized on derivatives	(71)	(148)
Gains (losses) recognized on derivatives	(121)	475
Gains (losses) recognized on hedged items	144	(447)
Excluded component of fair value hedges	0	0
Fair value hedges \| Interest rate contracts: \| Non-Interest Income, Other
Interest income:
Interest recognized on derivatives	0	0
Gains (losses) recognized on derivatives	(10)	23
Gains (losses) recognized on hedged items	10	(23)
Excluded component of fair value hedges	0	0
Cash flow hedges \| Investment Securities
Interest income:
Net income (expense) recognized on cash flow hedges	(2)	1
Cash flow hedges \| Loans, Including Loans Held for Sale
Interest income:
Net income (expense) recognized on cash flow hedges	(177)	(241)
Cash flow hedges \| Other
Interest income:
Net income (expense) recognized on cash flow hedges	3	2
Cash flow hedges \| Interest-bearing Deposits
Interest income:
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Securitized Debt Obligations
Interest income:
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Senior and Subordinated Notes
Interest income:
Net income (expense) recognized on cash flow hedges	0	0
Cash flow hedges \| Non-Interest Income, Other
Interest income:
Net income (expense) recognized on cash flow hedges	0	(1)
Cash flow hedges \| Interest rate contracts: \| Investment Securities
Interest income:
Realized gains (losses) reclassified from AOCI into net income	(2)	1
Cash flow hedges \| Interest rate contracts: \| Loans, Including Loans Held for Sale
Interest income:
Realized gains (losses) reclassified from AOCI into net income	(177)	(241)
Cash flow hedges \| Interest rate contracts: \| Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0
Cash flow hedges \| Interest rate contracts: \| Interest-bearing Deposits
Interest income:
Realized gains (losses) reclassified from AOCI into net income	0	0
Cash flow hedges \| Interest rate contracts: \| Securitized Debt Obligations
Interest income:
Realized gains (losses) reclassified from AOCI into net income	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
Cash flow hedges \| Interest rate contracts: \| Non-Interest Income, Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	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
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
Cash flow hedges \| Foreign exchange and other contracts \| Other
Interest income:
Realized gains (losses) reclassified from AOCI into net income	3	2
Cash flow hedges \| Foreign exchange and other contracts \| Interest-bearing Deposits
Interest income:
Realized gains (losses) reclassified from AOCI into net income	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
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
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)

Amortization of Basis Adjustment on Discontinued Hedges

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