Retirement and Benefit Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
The estimated net actuarial loss for the defined benefit pension plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost	$ 7
The increase in pension expense by lowering both the expected rate of return on the plan and the discount rate by 0.25%	1
Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months	18
Defined Benefit Plan Expected Future Benefit Payments Year Two	18
Defined Benefit Plan Expected Future Benefit Payments Year Three	16
Defined Benefit Plan Expected Future Benefit Payments Year Four	15
Defined Benefit Plan Expected Future Benefit Payments Year Five	14
Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter	63
Estimated future defined benefit plan contributions	4
Accumulated benefit obligation for all defined benefit plans	221		256
Plan assets managed	(200)	[1]	(185)	[1]
Bancorp's profit sharing plan expense	13		17		14
Net underfunded status	(21)		(71)
Deferred Profit Sharing [Member]
Defined Benefit Plan Disclosure [Line Items]
Expenses recognized for matching contributions to the Bancorp's defined contribution savings plan	43		42		40
Bancorp's profit sharing plan expense	32		46		35
Common Stock
Defined Benefit Plan Disclosure [Line Items]
Plan assets managed	4		3
Fifth Third Bank Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets managed through collective funds	$ 200		$ 123

[1] For further information on fair value hierarchy levels, see Note 1.