Related Party Transactions - Summary of the Bancorp's Activities with its Principal Shareholders, Directors and Executives (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Related Party Transactions
Outstanding balance on loans, net of participations and undrawn commitments	$ 67	$ 49
Commitments to Extend Credit
Related Party Transactions
Commitments	74,499	75,696
Commitments to Extend Credit | Due to related party
Related Party Transactions
Commitments	86	741
Commitments to Extend Credit | Directors and their affiliated companies | Due to related party
Related Party Transactions
Commitments	79	736
Commitments to Extend Credit | Executive officers | Due to related party
Related Party Transactions
Commitments	$ 7	$ 5