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, 2016	Dec. 31, 2015
Fifth Third Community Development Corporation Investments
Variable Interest Entity
Total Assets	$ 1,421	$ 1,455
Total Liabilities	357	367
Maximum Exposure	1,421	1,455
Private equity investments
Variable Interest Entity
Total Assets	176	211
Total Liabilities	0	0
Maximum Exposure	232	271
Loans Provided to VIEs
Variable Interest Entity
Total Assets	1,735	1,630
Total Liabilities	0	0
Maximum Exposure	$ 2,672	$ 2,599