Noninterest Revenue and Noninterest Expense - Card Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Credit cost amortization period	12 months
Direct loan origination costs amortization period	12 months
Total card income	$ 4,720	$ 5,497	$ 4,784
Interchange and merchant processing income
Disaggregation of Revenue [Line Items]
Total card income	36,222	33,847	31,021
Reward costs and partner payments
Disaggregation of Revenue [Line Items]
Total card income	(29,720)	(26,784)	(24,601)
All other
Disaggregation of Revenue [Line Items]
Total card income	$ (1,782)	$ (1,566)	$ (1,636)
Deferred revenues, recognition period	12 months
Minimum
Disaggregation of Revenue [Line Items]
Credit card revenue sharing agreement terms	5 years
Maximum
Disaggregation of Revenue [Line Items]
Credit card revenue sharing agreement terms	10 years