Derivative Instruments and Hedging Activities - Fair Value Hedge Derivatives (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Statement of Financial Position [Extensible Enumeration]	Available for sale securities	Available for sale securities
Hedged Liability, Statement of Financial Position [Extensible Enumeration]	Long-term debt	Long-term debt
Carrying amount of hedged asset	$ 12,249	$ 15,686
Carrying amount of hedged liability	(20,726)	(14,908)
Cumulative fair value hedging adjustment included in the carrying value of hedged long-term debt	11	(7)
Cumulative basis adjustments to the amortized cost basis of the close portfolios	2	(47)
Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative fair value hedging adjustments related to securities which hedge accounting has been discontinued	5
Available for sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative fair value hedging adjustment included in the amortized cost of hedged AFS securities	(16)	(292)
Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative fair value hedging adjustment included in the carrying value of hedged long-term debt	(6)	7
Debt Securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amortized cost basis of closed portfolio hedges	1,100	2,500
Amount of designated hedged items of closed portfolio hedges	771	2,000
Cumulative basis adjustments to the amortized cost basis of the close portfolios	2	(47)
Cumulative fair value hedging adjustments related to securities which hedge accounting has been discontinued	$ 26	$ 2

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