Fair Value (Nonrecurring Fair Value Measurements) (Details) - Fair Value, Nonrecurring - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	$ 405		$ 448
Nonrecurring Assets - Gains (Losses)	(89)	$ (31)
Level 3 | Nonaccrual loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	310		280
Nonrecurring Assets - Gains (Losses)	(79)	(24)
Level 3 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	77		135
Nonrecurring Assets - Gains (Losses)	(5)	(6)
Level 3 | OREO and foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	7		10
Nonrecurring Assets - Gains (Losses)
Level 3 | Long-lived assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	11		23
Nonrecurring Assets - Gains (Losses)	(5)	$ (1)
Level 1 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	$ 37		$ 42