Fair Value (Schedule of Carrying Values and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Held-to-maturity investment securities	$ 10,105	$ 10,466
Time deposits	10,221	9,996
Long-term debt	544	542
Level 2 | Carrying value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Held-to-maturity investment securities	10,209	10,382
Time deposits	10,221	9,996
Long-term debt	544	542
Level 2 | Fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Held-to-maturity investment securities	10,105	10,466
Time deposits	10,179	9,964
Long-term debt	498	494
Level 3 | Carrying value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases (including loans held for sale), net of allowance	57,422	57,148
Level 3 | Fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases (including loans held for sale), net of allowance	$ 55,502	$ 54,832