Regulatory Capital Requirements (Capital and Risk-Based Capital and Leverage Ratios for the Bancorp and its Significant Subsidiary Banks) (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fifth Third Bancorp
Risk Based Ratios
CET1 capital (to risk-weighted assets)	10.39%	9.82%	[1]
Tier I risk-based capital (to risk-weighted assets)	11.50%	10.93%	[1]
Total risk-based capital (to risk-weighted assets)	15.02%	14.13%	[1]
Tier I leverage (to quarterly average assets)	9.90%	9.54%	[1]
Risk Based Capital
CET1 capital (to risk-weighted assets)	$ 12,426	$ 11,917
Tier I risk-based capital (to risk-weighted assets)	13,756	13,260
Total risk-based capital (to risk weighted assets)	17,972	17,134
Tier I leverage (to quarterly average assets)	$ 13,756	$ 13,260
Fifth Third Bank
Risk Based Ratios
CET1 capital (to risk-weighted assets)	11.92%	11.92%	[1]
Tier I risk-based capital (to risk-weighted assets)	11.92%	11.92%	[1]
Total risk-based capital (to risk-weighted assets)	13.76%	13.12%	[1]
Tier I leverage (to quarterly average assets)	10.30%	10.43%	[1]
Risk Based Capital
CET1 capital (to risk-weighted assets)	$ 14,015	$ 14,216
Tier I risk-based capital (to risk-weighted assets)	14,015	14,216
Total risk-based capital (to risk weighted assets)	16,175	15,642
Tier I leverage (to quarterly average assets)	$ 14,015	$ 14,216

[1] (a) Ratios not restated for the adoption of the amended guidance of ASU 2015-03 “Simplifying the Presentation of Debt Issuance Costs.” For further information, r efer to Note 1 .