Fair Values of Assets and Liabilities (Significant Unobservable Level 3 Inputs Recurring Basis) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs [Line Items]
Residential mortgage loans measured at fair value		$ 167	$ 108
Derivative instruments		1,852	2,080
Residential mortgage loans
Fair Value Inputs [Line Items]
Residential mortgage loans measured at fair value		167	108
IRLCs, net
Fair Value Inputs [Line Items]
Derivative instruments		15	12
Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Derivative instruments		262	415
Swap associated with the sale of Visa, Inc. Class B shares
Fair Value Inputs [Line Items]
Derivative instruments		$ (61)	$ (49)
Lower limit | Residential mortgage loans
Fair Value Inputs [Line Items]
Interest rate risk factor		(9.20%)	(7.20%)
Lower limit | IRLCs, net
Fair Value Inputs [Line Items]
Loan closing rates		5.80%	8.80%
Lower limit | Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Expected term (years)		2 years	2 years
Expected volatility	[1]	22.60%	22.90%
Lower limit | 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	Dec. 31, 2015
Maximum | Residential mortgage loans
Fair Value Inputs [Line Items]
Interest rate risk factor		16.50%	17.70%
Credit risk factor		80.50%	46.60%
Maximum | IRLCs, net
Fair Value Inputs [Line Items]
Loan closing rates		94.00%	86.70%
Maximum | Stock warrants associated with Vantiv Holding, LLC
Fair Value Inputs [Line Items]
Expected term (years)		13 years 6 months	14 years 6 months
Expected volatility	[1]	31.20%	32.20%
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	Jun. 30, 2020
Weighted average | Residential mortgage loans
Fair Value Inputs [Line Items]
Interest rate risk factor		3.10%	5.00%
Credit risk factor		1.30%	1.80%
Weighted average | IRLCs, net
Fair Value Inputs [Line Items]
Loan closing rates		76.30%	65.20%
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]	25.90%	26.50%

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