Premises and Equipment (Schedule of Premises and Equipment) (Details) - USD ($) $ in Millions |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | $ 4,610 | $ 4,614 |
| Accumulated depreciation and amortization | (2,713) | (2,654) |
| Premises and equipment, net | 1,897 | 1,960 |
| Land | ||
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | 434 | 446 |
| Premises and improvements | ||
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | 1,678 | 1,783 |
| Furniture and equipment | ||
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | 1,041 | 1,023 |
| Software | ||
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | 836 | 756 |
| Leasehold improvements | ||
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | 413 | 407 |
| Construction in progress | ||
| Property, Plant and Equipment [Line Items] | ||
| Premises and equipment, gross | $ 208 | $ 199 |