Fair Value (Fair Value Option - Changes in Fair Value) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Loans held for sale | Residential mortgage loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	$ 15	$ (40)
Loans held for sale | Commercial mortgage loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	1	6
Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	4	21
Other assets
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	(14)	$ (7)
Other liabilities
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains (losses) - FVO: changes in fair value	$ (20)