Fair Value (Fair Value Option - Changes in Fair Value) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Loans Held For Sale | Residential Mortgages
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (Losses) - FVO: Changes in Fair Value	$ 32	$ (80)	$ 152
Loans Held For Sale | Commercial Mortgages
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (Losses) - FVO: Changes in Fair Value	53	52	115
Loans | Residential Mortgages
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (Losses) - FVO: Changes in Fair Value	26	42	80
Other assets
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (Losses) - FVO: Changes in Fair Value	7	(16)	28
Other liabilities
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (Losses) - FVO: Changes in Fair Value	$ (41)	$ (67)