Credit Quality and the Allowance for Loan and Lease Losses - Summary of the Amortized Cost Basis of the Bancorp's Collateral Dependent Loans (Details) $ in Millions	Jun. 30, 2020 USD ($)
Financing Receivable, Impaired
Total loans and leases	$ 1,156
Commercial
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	969
Commercial | Commercial and industrial loans
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	796
Commercial | Commercial mortgage owner-occupied loans
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	46
Commercial | Commercial mortgage nonowner-occupied loans
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	83
Commercial | Commercial construction loans
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	20
Commercial | Commercial leases
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	24
Residential Mortgage
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	107
Consumer
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	80
Consumer | Home equity
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	72
Consumer | Indirect secured consumer loans
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	8
Consumer | Other consumer loans
Financing Receivable, Impaired
Loans and leases receivable, allowance for amortized cost basis	$ 0