Fair Value (Nonrecurring Fair Value Measurements) (Details) - Fair Value, Nonrecurring - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	$ 980		$ 980		$ 802
Nonrecurring Assets - Gains (Losses)	(188)	$ (114)	(254)	$ (198)
Level 3 | Nonaccrual loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	769		769		578
Nonrecurring Assets - Gains (Losses)	(192)	(99)	(245)	(174)
Level 3 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	170		170		203
Nonrecurring Assets - Gains (Losses)	8	(5)	(1)	(8)
Level 3 | Loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	25		25
Nonrecurring Assets - Gains (Losses)
Level 3 | OREO and foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	6		6		12
Nonrecurring Assets - Gains (Losses)	(1)		(2)	(1)
Level 3 | Long-lived assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	10		10		9
Nonrecurring Assets - Gains (Losses)	(3)	$ (10)	(6)	$ (15)
Level 2 | Loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value	$ 25		$ 25
Level 1 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring Assets - Fair Value					$ 30