Derivative Financial Instruments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2009
Derivative [Line Items]
Valuation adjustments related to the credit risk associated with counterparties of customer accomodation derivative contracts	$ 13	$ 16
Maximum length of time hedged in cash flow hedge	4 years 9 months
Percentage of Vantiv Holding, LLC sold to Advent for cash and warrants			51.00%
Credit Risk
Derivative [Line Items]
Credit Risk Derivatives Average Remaining Life	2 years 3 months 18 days
Interest Rate Contract
Derivative [Line Items]
Fair value of risk participation agreements	2	2
Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Deferred gains, net of tax, on cash flow hedges were recorded in accumulated other comprehensive income	47	23
Net deferred gains, net of tax, recorded in accumulated other comprehensive income are expected to be reclassified into earnings during the next twelve months	44
Interest Rate Contract | Lender Concentration Risk
Derivative [Line Items]
Notional amount of the risk participation agreements	1,154	1,113
Total collateral (up to and exceeding 100% of the net position)
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	952	830
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 613	$ 574