Income Taxes (Reconciliation Between the Statutory U.S. Income Tax Rate and the Bancorp's Effective Tax Rate) (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation Of Statutory Federal Tax Rate
Statutory tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	1.30%	1.70%	1.40%
Tax-exempt income	(2.70%)	(1.70%)	(1.40%)
Low-income housing tax credits	(7.90%)	(6.60%)	(7.00%)
Other tax credits	(0.90%)	(0.90%)	(1.10%)
Other, net	(0.40%)	0.30%	0.00%
Effective tax rate	24.40%	27.80%	26.90%