Fair Value of Assets and Liabilities - Gains/(losses) on Nonrecurring Fair Value Measurements (Details) - Non Recurring - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net gains/(losses),loans and leases	$ (19)	$ 0	$ (23)	$ (1)
Net gains/(losses), Other assets	(1)	(1)	(1)	(2)
Gains (losses) on financial assets measured on non-recurring basis	(21)	(4)	(26)	(7)
SBAs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net gains/(losses), loans held for sale - SBAs and USDA	$ (1)	$ (3)	$ (2)	$ (4)