Derivative and Hedging Activities - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gains on derivatives	$ 74,000,000	$ 74,000,000	$ 10,000,000
Interest , loans and leases held-for-sale		7,000,000
Derivative, amount of hedged item	5,900,000,000	5,900,000,000
Fair value of interest rate fair value hedging instruments		(24,000,000)
Amount of gain (loss), net of tax, to be reclassified during the next 12 months	80,000,000	80,000,000
Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Repayment of FHLB loan advances	2,000,000,000
Amount of gain (loss) recognized in accumulated other comprehensive loss	5,000,000
Interest rate swaps on FHLB advances \| Designated as Hedging Instrument \| Cash flow hedging
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 0	$ 0	$ 5,500,000,000

Amount, after tax, of accumulated gain (loss) on derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount of hedged item in hedging relationship. Excludes hedged asset or liability.

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Nominal or face amount used to calculate payment on derivative.

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Amount of repayments and penalties incurred in the satisfaction or roll-over of Federal Home Loan Bank (FHLB) advance.

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Amount of unrealized gain (loss) related to the fair value of interest rate derivatives designated as fair value hedging instruments, as offset by the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

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The amount of interest and fee income earned from loans held-for-sale, including mortgage loans, and interest earned from direct financing and sales-type leases held-for-sale.

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The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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