Loans and Allowance for Credit Losses - Investments by Credit Quality (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 46,690	$ 43,186
Loans held-for-sale	92	14
Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,960	1,980
Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	42,256	37,800
Investment grade | Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,900
Sub-investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,798	4,687
Sub-investment grade | Overdrafts
Financing Receivable, Credit Quality Indicator [Line Items]
Total	60
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total	242	249
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total	213	259
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total	181	191
Commercial and Financial
Financing Receivable, Credit Quality Indicator [Line Items]
Total	44,219	40,344
Commercial and Financial | Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	40,854	35,831
Commercial and Financial | Sub-investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,157	4,278
Commercial and Financial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total	110	187
Commercial and Financial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total	48	48
Commercial and Financial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total	50	0
Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,471	2,842
Commercial Real Estate | Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,402	1,969
Commercial Real Estate | Sub-investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	641	409
Commercial Real Estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total	132	62
Commercial Real Estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total	165	211
Commercial Real Estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 131	$ 191