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Derivatives (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Counterparty default losses on forward contracts	$ 0	$ 0	$ 0	$ 0
Credit Derivatives [Line Items]
Commitments
Collateral required to be posted under agreements	89		89		87
Variation Margin Adjustment	107		107		174
Interest rate futures
Credit Derivatives [Line Items]
Derivative, notional amount	194		194		187
Mortgage-Backed Security
Credit Derivatives [Line Items]
Derivative, notional amount	36		36		12
Interest rate swaps
Credit Derivatives [Line Items]
Derivative Asset, Notional Amount	4,500		4,500		4,300
Derivative Liability, Notional Amount	4,500		4,500		4,400
Commitments To Originate Loans Held For Sale
Credit Derivatives [Line Items]
Commitments	59		59		46
Interest rate forward sales commitments
Credit Derivatives [Line Items]
Commitments	$ 82		$ 82		$ 77

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