Financial Derivatives (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Gain (loss) on net investment hedge derivatives	$ 24,000,000	$ (53,000,000)	$ 119,000,000
Cash and securities held to collateralize net derivative assets	2,400,000,000
Cash and securities pledged to collateralize net derivative liabilities	2,300,000,000
Net derivative liabilities with credit-risk contingent features	3,900,000,000	4,200,000,000
Collateral posted	1,100,000,000	1,000,000,000.0
Maximum additional amount of collateral exposure	2,800,000,000	3,200,000,000
Cash Flow Hedging | Interest rate contracts
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	600,000,000
Cash flow hedge gain (loss) to be reclassified within twelve months, net of tax	$ 500,000,000
Maximum length of time over which forecasted loan cash flows are hedged	10 years
Net Investment Hedging | Foreign exchange contracts
Derivative [Line Items]
Gain (loss) from components excluded from assessment of net investment hedge effectiveness net	$ 0	$ 0	$ 0