Fair Values of Assets and Liabilities (Significant Unobservable Level 3 Inputs) (Detail) (Fair Value, Inputs, Level 3, USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Commercial Loans Held For Sale | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets			$ 13
Commercial and Industrial Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	431		79
Commercial Mortgage Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	63		59
Commercial Construction Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	3		8
Commercial Leases | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	1
Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	915		679
OREO Property | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	109		114
Residential mortgage loans | Fair value, recurring
Quantitative information about level 3 fair value measurements
Residential mortgage loans	89		76
IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Derivative instruments	24		102
Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Derivative instruments	293		197
Swap associated with the sale of Visa, Inc. Class B shares | Fair value, recurring
Quantitative information about level 3 fair value measurements
Derivative instruments	$ (35)		$ (21)
Minimum | Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Prepayment speed	0.00%		0.00%
Discount rate	9.40%		9.40%
Minimum | Residential mortgage loans | Fair value, recurring
Quantitative information about level 3 fair value measurements
Interest rate risk factor	(19.90%)		(91.00%)
Credit risk factor	0.00%		2.30%
Minimum | IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Loan closing rates	3.10%		9.80%
Minimum | Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Expected term (years)	2 years		2 years
Expected volatility	21.00%	[1]	27.70%	[1]
Minimum | Swap associated with the sale of Visa, Inc. Class B shares | Fair value, recurring
Quantitative information about level 3 fair value measurements
Timing of the resolution of the covered litigation	2014-03-31		2013-06-30
Maximum | Commercial and Industrial Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Default rates			100.00%
Maximum | Commercial Mortgage Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Default rates			100.00%
Maximum | Commercial Construction Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Default rates			100.00%
Maximum | Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Prepayment speed	100.00%		100.00%
Discount rate	18.00%		18.00%
Maximum | Residential mortgage loans | Fair value, recurring
Quantitative information about level 3 fair value measurements
Interest rate risk factor	12.20%		16.60%
Credit risk factor	56.40%		68.40%
Maximum | IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Loan closing rates	97.20%		95.00%
Maximum | Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Expected term (years)	15 years 9 months 18 days		16 years 9 months
Expected volatility	33.40%	[1]	40.60%	[1]
Maximum | Swap associated with the sale of Visa, Inc. Class B shares | Fair value, recurring
Quantitative information about level 3 fair value measurements
Timing of the resolution of the covered litigation	2017-03-31		2015-06-30
Weighted average | Commercial Loans Held For Sale | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Cost to sell	10.00%		10.00%
Weighted average | Residential mortgage loans | Fair value, recurring
Quantitative information about level 3 fair value measurements
Interest rate risk factor	3.50%		6.50%
Credit risk factor	3.30%		4.60%
Weighted average | IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Loan closing rates	66.40%		60.10%
Weighted average | Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Expected term (years)	5 years 1 month 6 days		6 years 2 months 12 days
Expected volatility	27.80%	[1]	34.20%	[1]
Fixed | Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Prepayment speed	11.40%		16.90%
Discount rate	10.40%		10.60%
Adjustable | Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Prepayment speed	25.70%		27.10%
Discount rate	11.60%		11.70%

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