Commitments (Commitments, Contingent Liabilities and Guarantees - Additional Information) (Detail) - USD ($) shares in Millions	3 Months Ended			6 Months Ended			12 Months Ended
	Jun. 30, 2016		Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015	Dec. 31, 2015		Dec. 31, 2013	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Loss Contingencies
Fifth Third Securities, Inc. (FTS) acted as the remarketing agent to issuers of VRDNs	$ 891,000,000			$ 891,000,000			$ 1,100,000,000
Letters of credit	2,737,000,000			2,737,000,000			3,055,000,000
Total Variable Rate Demand Notes	1,100,000,000			1,100,000,000			1,300,000,000
Margin account balance held by the brokerage clearing agent	14,000,000			14,000,000			10,000,000
Amount in excess of amounts reserved	43,000,000			43,000,000
Credit loss reserve	1,299,000,000	[1],[2]	$ 1,293,000,000	1,299,000,000	[1],[2]	$ 1,293,000,000	1,272,000,000	[1],[3]		$ 1,295,000,000	$ 1,300,000,000	$ 1,322,000,000
Residential Mortgage
Loss Contingencies
Repurchase Claim Settlement									$ 25,000,000
Amount in excess of amounts reserved	27,000,000			27,000,000
Outstanding balances on residential mortgage loans sold with representation and warranty provisions	21,000,000		32,000,000	21,000,000		32,000,000	25,000,000			$ 23,000,000	$ 36,000,000	$ 35,000,000
Outstanding balances on residential mortgage loans sold with credit recourse	$ 429,000,000			$ 429,000,000			$ 465,000,000
Delinquency Rates	2.80%			2.80%			3.00%
Credit loss reserve	$ 8,000,000			$ 8,000,000			$ 9,000,000
Make Whole Payments			1,000,000			2,000,000
Repurchased Outstanding Principal	2,000,000		7,000,000	6,000,000		16,000,000
Repurchase Demand Request	4,000,000		$ 11,000,000	10,000,000		$ 20,000,000
Outstanding Repurchase Demand Inventory	4,000,000						4,000,000
Secured Debt
Loss Contingencies
Fully and unconditionally guaranteed certain long-term borrowing obligations issued by wholly-owned issuing trust entities	62,000,000			62,000,000			$ 62,000,000
Standby Letters of Credit
Loss Contingencies
Reserve for unfunded commitments	$ 2,000,000			$ 2,000,000
Standby letters of credit as a percentage of total letters of credit	99.00%			99.00%			99.00%
Standby Letters of Credit | Secured Debt
Loss Contingencies
Standby letters of credit as a percentage of total letters of credit	65.00%			65.00%			65.00%
Variable Rate Demand Note
Loss Contingencies
Letters of credit	$ 167,000,000			$ 167,000,000			$ 187,000,000
Letters of credit issued by the Bancorp related to variable rate demand notes	719,000,000			719,000,000			921,000,000
Variable Rate Demand Note | Trading Securities
Loss Contingencies
Total Variable Rate Demand Notes	3,000,000			3,000,000
Other Liabilities
Loss Contingencies
Reserve for unfunded commitments	151,000,000			151,000,000			138,000,000
Other Liabilities | Residential Mortgage
Loss Contingencies
Outstanding balances on residential mortgage loans sold with representation and warranty provisions	21,000,000			21,000,000			25,000,000
Private Mortgage Reinsurance
Loss Contingencies
Total outstanding reinsurance coverage	1,000,000			1,000,000			27,000,000
Approximate reserve related to exposures within the reinsurance portfolio							2,000,000
Carrying value of collateral released to insurer due to terminated reinsurance agreement	6,000,000			$ 6,000,000
Payment received related to the difference between the release of assets and the reserve liability assumed	$ 4,000,000
Private Mortgage Reinsurance | Lower Limit
Loss Contingencies
Reinsurance coverage ranges of the total PMI coverage	5.00%			5.00%
Private Mortgage Reinsurance | Upper Limit
Loss Contingencies
Reinsurance coverage ranges of the total PMI coverage	10.00%			10.00%
Visa Litigation
Loss Contingencies
Recorded share of litigation formally settled by Visa and for probable future litigation settlements	$ 99,000,000			$ 99,000,000			$ 61,000,000
Visa deposited into the litigation escrow account																			$ 3,000,000
Visa
Loss Contingencies
Visa IPO, shares of Visa's Class B common stock received																			10.1
Visa deposited into the litigation escrow account													$ 450,000,000	$ 150,000,000	$ 1,565,000,000	$ 400,000,000	$ 800,000,000	$ 500,000,000

[1] Includes $ 128 and $ 152 of cash and due from banks, $ 1,853 and $ 2,537 of portfolio loans and leases , $ (28) and $ (28) of ALLL, $ 11 and $ 14 of other assets, $ 3 and $ 3 of other liabilities , and $ 1,744 and $ 2,487 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2016 and December 31, 2015 , respectively. For further information refer to Note 9 .

[2] Includes $ 3 related to leveraged leases at June 30, 2016 .

[3] Includes $ 5 related to leveraged leases at December 31, 2015 .