Fair Values of Assets and Liabilities (Significant Unobservable Level 3 Inputs Recurring Basis) (Detail) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value Inputs [Line Items]
Derivative instruments		$ 2,552		$ 2,080
Residential mortgage loans
Fair Value Inputs [Line Items]
Residential mortgage loans measured at FV		173	$ 109
IRLCs, net
Fair Value Inputs [Line Items]
Derivative instruments		19	10
Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Derivative instruments		630	358
Swap associated with the sale of Visa, Inc. Class B shares
Fair Value Inputs [Line Items]
Derivative instruments		$ (58)	$ (53)
Minimum | Residential mortgage loans
Fair Value Inputs [Line Items]
Interest rate risk factor		(8.00%)	(11.00%)
Minimum | IRLCs, net
Fair Value Inputs [Line Items]
Loan closing rates		14.90%	4.00%
Minimum | Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Expected term (years)		2 years	2 years
Expected volatility	[1]	22.70%	23.00%
Minimum | Swap associated with the sale of Visa, Inc. Class B shares
Fair Value Inputs [Line Items]
Timing of the resolution of the covered litigation		Dec. 31, 2016	Jun. 30, 2015
Maximum | Residential mortgage loans
Fair Value Inputs [Line Items]
Interest rate risk factor		16.30%	18.50%
Credit risk factor		80.50%	58.60%
Maximum | IRLCs, net
Fair Value Inputs [Line Items]
Loan closing rates		87.60%	95.00%
Maximum | Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Expected term (years)		13 years 9 months	14 years 9 months 18 days
Expected volatility	[1]	32.40%	32.00%
Maximum | Swap associated with the sale of Visa, Inc. Class B shares
Fair Value Inputs [Line Items]
Timing of the resolution of the covered litigation		Mar. 31, 2021	Dec. 31, 2019
Proportional share of covered litigation loss in excess of escrow funds			$ 17
Weighted average | Residential mortgage loans
Fair Value Inputs [Line Items]
Interest rate risk factor		4.00%	4.50%
Credit risk factor		0.90%	1.70%
Weighted average | IRLCs, net
Fair Value Inputs [Line Items]
Loan closing rates		61.30%	65.00%
Weighted average | Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Expected term (years)		5 years 10 months 24 days	6 years
Expected volatility	[1]	26.70%	26.60%
Weighted average | Swap associated with the sale of Visa, Inc. Class B shares
Fair Value Inputs [Line Items]
Proportional share of covered litigation loss in excess of escrow funds			$ 17

[1] Based on historical and implied volatilities of Vantiv, Inc. and comparable companies assuming similar expected terms.