Derivatives and Hedging Activities (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Margin on interest rate swap not netted	$ 175	$ 8
Hedged Liability, Statement of Financial Position [Extensible Enumeration]	Outstanding balance	Outstanding balance
Carrying values of hedged liabilities	$ 11,700	$ 7,800
Cumulative amount of fair value hedging adjustments	53	(236)
Increase (decrease) in interest expense on long term debt and other	189	(57)	$ (256)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	25,300	21,700
Other Expense
Derivatives, Fair Value [Line Items]
Gain (loss) in changes in fair value of derivatives not designated as hedges	82	8	(21)
Credit Valuation Adjustment
Derivatives, Fair Value [Line Items]
Derivative, amount of hedged item	0	0
Fair Value Hedges | Fixed-Rate Debt Obligations
Derivatives, Fair Value [Line Items]
Derivative, amount of hedged item	11,700	8,100
Net Investment Hedges
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	14,100	12,500
Gain (loss) on net investment hedges, net of taxes	(640)	237	176
Reclassifications out of AOCI	0	0	$ 0
Embedded Derivative | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	78	78
Fair value of embedded derivative asset, gross	18	27
Embedded Derivative | Noninterest Income | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Gain (loss) on embedded derivative	$ (9)	$ 4