Loans and Allowance for Credit Losses - Investments by Credit Quality (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 43,186	$ 36,631
Overdrafts	1,980	2,270
Loans held-for-sale	14
Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	37,800	32,024
Overdrafts	1,840
Speculative
Financing Receivable, Credit Quality Indicator [Line Items]
Total	4,687	3,995
Overdrafts	140
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total	249	304
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total	259	238
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total	191	70
Commercial and Financial
Financing Receivable, Credit Quality Indicator [Line Items]
Total	40,344	33,562
Commercial and Financial | Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	35,831	29,737
Commercial and Financial | Speculative
Financing Receivable, Credit Quality Indicator [Line Items]
Total	4,278	3,546
Commercial and Financial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total	187	242
Commercial and Financial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total	48	14
Commercial and Financial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	23
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,842	3,069
Commercial real estate | Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,969	2,287
Commercial real estate | Speculative
Financing Receivable, Credit Quality Indicator [Line Items]
Total	409	449
Commercial real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Total	62	62
Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Total	211	224
Commercial real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 191	$ 47