Derivative Instruments and Hedging Activities - Effect of Fair Value Hedge Derivatives (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest income, receipts	$ 14	$ 13	$ 32	$ 16
Interest expense, receipts	(14)		(24)
Interest rate swaps \| Interest Revenue
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives designated as hedging instruments	(94)	38	(255)	195
Interest rate swaps \| Interest Expense
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives designated as hedging instruments	(9)	0	18	0
Debt Securities and Hedged Available-for-Sale Securities \| Interest Revenue
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged items	94	(40)	255	(197)
Long-term debt \| Interest Expense
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged items	$ 9	$ 0	$ (16)	$ 0

Interest Expense, Fair Value Hedge Derivative Instrument, Increase (Decrease)

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- Definition

Interest Income, Fair Value Hedge Derivative Instrument, Increase (Decrease)

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- Definition

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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