Long-Term Debt (Summary of the Bancorp's Long-Term Borrowings) (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument
Long-term debt	$ 14,970	$ 14,426
Parent Company
Debt Instrument
Long-term debt	7,513
Parent Company | Senior Debt Obligations | Fixed Rate 2.30 Percent Notes Due 2019
Debt Instrument
Long-term debt	$ 0	500
Interest rate	2.30%
Parent Company | Senior Debt Obligations | Fixed Rate 2.875 Percent Due 2020
Debt Instrument
Long-term debt	$ 1,099	1,098
Interest rate	2.875%
Parent Company | Senior Debt Obligations | Fixed Rate 2.60 Percent Notes Due 2022
Debt Instrument
Long-term debt	$ 699	698
Interest rate	2.60%
Parent Company | Senior Debt Obligations | Fixed Rate 3.50 Percent Due 2022
Debt Instrument
Long-term debt	$ 499	498
Interest rate	3.50%
Parent Company | Senior Debt Obligations | Fixed Rate 3.95 Percent Notes Due 2028
Debt Instrument
Long-term debt	$ 646	646
Interest rate	3.95%
Parent Company | Senior Debt Obligations | Floating Rate 2.37 Percent Notes Due 2021
Debt Instrument
Long-term debt	$ 250	250
Interest rate	2.37%
Parent Company | Senior Debt Obligations | Fixed Rate 3.65 Percent Notes Due 2024
Debt Instrument
Long-term debt	$ 1,493	0
Interest rate	3.65%
Parent Company | Senior Debt Obligations | Fixed Rate 2.375 Percent Notes Due 2025
Debt Instrument
Long-term debt	$ 746	0
Interest rate	2.375%
Parent Company | Subordinated Debt | Fixed Rate 4.30 Notes Due 2024
Debt Instrument
Long-term debt	$ 748	747
Interest rate	4.30%
Parent Company | Subordinated Debt | Fixed Rate 8.25 Percent Notes Due 2038
Debt Instrument
Long-term debt	$ 1,333	1,238
Interest rate	8.25%
Subsidiaries
Debt Instrument
Long-term debt	$ 7,457
Subsidiaries | Debt Other Variable Percent Due 2020 Through 2040
Debt Instrument
Long-term debt	153	56
Subsidiaries | Variable Interest Entity, Primary Beneficiary | Fixed Rate | Automobile Loans
Debt Instrument
Long-term debt	$ 1,147	568
Subsidiaries | Variable Interest Entity, Primary Beneficiary | Fixed Rate | Automobile Loans | Lower limit
Debt Instrument
Interest rate	1.80%
Subsidiaries | Variable Interest Entity, Primary Beneficiary | Fixed Rate | Automobile Loans | Upper Limit
Debt Instrument
Interest rate	2.69%
Subsidiaries | Variable Interest Entity, Primary Beneficiary | Floating Rate | Automobile Loans
Debt Instrument
Long-term debt	$ 42	11
Interest rate	1.91%
Subsidiaries | Senior Debt Obligations | Fixed Rate 2.30 Percent Notes Due 2019
Debt Instrument
Long-term debt	$ 0	750
Interest rate	2.30%
Subsidiaries | Senior Debt Obligations | Fixed Rate 2.375 Percent Notes Due 2019
Debt Instrument
Long-term debt	$ 0	850
Interest rate	2.375%
Subsidiaries | Senior Debt Obligations | Fixed Rate 1.625 Percent Notes Due 2019
Debt Instrument
Long-term debt	$ 0	743
Interest rate	1.625%
Subsidiaries | Senior Debt Obligations | Fixed Rate 2.20 Percent Notes Due 2020
Debt Instrument
Long-term debt	$ 752	742
Interest rate	2.20%
Subsidiaries | Senior Debt Obligations | Floating Rate 3.412 Percent Notes Due 2019
Debt Instrument
Long-term debt	$ 0	250
Interest rate	3.412%
Subsidiaries | Senior Debt Obligations | Floating Rate 2.186 Percent Notes Due 2020
Debt Instrument
Long-term debt	$ 300	300
Interest rate	2.186%
Subsidiaries | Senior Debt Obligations | Fixed Rate 2.25 Percent Notes Due 2021
Debt Instrument
Long-term debt	$ 1,249	1,248
Interest rate	2.25%
Subsidiaries | Senior Debt Obligations | Fixed rate 2.875 percent Notes due 2021
Debt Instrument
Long-term debt	$ 848	847
Interest rate	2.875%
Subsidiaries | Senior Debt Obligations | Fixed Rate 3.35 Percent Notes Due 2021
Debt Instrument
Long-term debt	$ 508	502
Interest rate	3.35%
Subsidiaries | Senior Debt Obligations | Fixed Rate 3.95 Percent Notes Due 2025
Debt Instrument
Long-term debt	$ 797	764
Interest rate	3.95%
Subsidiaries | Senior Debt Obligations | Floating Rate 2.376 Percent Notes Due 2021
Debt Instrument
Long-term debt	$ 299	299
Interest rate	2.376%
Subsidiaries | Senior Debt Obligations | Floating Rate 2.549 Percent Notes Due 2022
Debt Instrument
Long-term debt	$ 299	0
Interest rate	2.549%
Subsidiaries | Subordinated Debt | Fixed Rate 3.85 Percent Notes Due 2026
Debt Instrument
Long-term debt	$ 748	747
Interest rate	3.85%
Subsidiaries | Subordinated Debt | Fixed Rate 4.00 Percent Notes Due 2027
Debt Instrument
Long-term debt	$ 171	0
Interest rate	4.00%
Subsidiaries | Junior Subordinated Debt | Floating Rate 3.31% - 3.58% Debentures Due 2035
Debt Instrument
Long-term debt	$ 53	52
Subsidiaries | Junior Subordinated Debt | Floating Rate 3.31% - 3.58% Debentures Due 2035 | Lower limit
Debt Instrument
Interest rate	3.31%
Subsidiaries | Junior Subordinated Debt | Floating Rate 3.31% - 3.58% Debentures Due 2035 | Upper Limit
Debt Instrument
Interest rate	3.58%
Subsidiaries | Junior Subordinated Debt | FHLB Advances 0.05 To 6.87 Percent Due 2020 Through 2047
Debt Instrument
Long-term debt	$ 91	$ 22
Subsidiaries | Junior Subordinated Debt | FHLB Advances 0.05 To 6.87 Percent Due 2020 Through 2047 | Lower limit
Debt Instrument
Interest rate	0.05%
Subsidiaries | Junior Subordinated Debt | FHLB Advances 0.05 To 6.87 Percent Due 2020 Through 2047 | Upper Limit
Debt Instrument
Interest rate	6.87%