Fair Value Measurements, Gains (Losses) on Assets with Nonrecurring Fair Value Adjustments (Details) - Nonrecurring [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	$ (411)	$ (447)
Loans held for sale [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	(9)	12
Loans [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	(448)	(263)
Loans [Member] \| Total Commercial [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	(337)	(143)
Loans [Member] \| Total Consumer [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	(111)	(120)
Equity securities [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	56	(177)
Other assets class [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis Increase (Decrease) [Line Items]
Total	$ (10)	$ (19)