VIE (Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses) (Detail) - Variable Interest Entity, Not Primary Beneficiary - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fifth Third Community Development Corporation Investments
Variable Interest Entity
Total Assets	$ 1,435	$ 1,198
Total Liabilities	428	376
Maximum Exposure	1,435	1,198
Private equity investments
Variable Interest Entity
Total Assets	89	41
Total Liabilities	0	0
Maximum Exposure	164	73
Lease pool entities
Variable Interest Entity
Total Assets	74
Total Liabilities	0
Maximum Exposure	74
Loans Provided to VIEs
Variable Interest Entity
Total Assets	2,715	2,331
Total Liabilities	0	0
Maximum Exposure	$ 4,083	$ 3,617