Capital and Risk-Based Capital and Leverage Ratios for the Bancorp and its Significant Subsidiary Banks (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fifth Third Bancorp (Consolidated)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital (to risk-weighted assets)	14.08%	14.42%
Tier I capital (to risk-weighted assets)	10.36%	10.65%
Tier I leverage (to average assets)	9.64%	10.05%
Total risk-based capital (to risk weighted assets)	$ 16,441	$ 15,816
Tier I capital (to risk-weighted assets)	12,094	11,685
Tier I leverage (to average assets)	12,094	11,685
Fifth Third Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital (to risk-weighted assets)	12.86%	12.74%
Tier I capital (to risk-weighted assets)	11.52%	11.28%
Tier I leverage (to average assets)	10.73%	10.65%
Total risk-based capital (to risk weighted assets)	14,795	13,721
Tier I capital (to risk-weighted assets)	13,245	12,145
Tier I leverage (to average assets)	$ 13,245	$ 12,145