Fair Value (Fair Value Option - Changes in Fair Value) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Loans held for sale | Residential mortgage loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	$ 18	$ (3)	$ 32	$ 14
Loans held for sale | Commercial mortgage loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	3	6	12	29
Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	6	8	18	17
Other assets
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	17		20	(12)
Other liabilities
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	$ (3)		$ (12)	$ (41)