Fair Values of Assets and Liabilities (Significant Unobservable Level 3 Inputs) (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Commercial Loans Held For Sale | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	$ 2		$ 8
Commercial and Industrial Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Default rates	100.00%		100.00%
Fair value measurements nonrecurring assets	83		77
Commercial Mortgage Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Default rates	100.00%		100.00%
Fair value measurements nonrecurring assets	35		95
Commercial Construction Loans | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Default rates	100.00%		100.00%
Fair value measurements nonrecurring assets	8		26
Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	894		736
OREO Property | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Fair value measurements nonrecurring assets	112		134
Residential mortgage loans | Fair value, recurring
Quantitative information about level 3 fair value measurements
Residential mortgage loans	83		76
IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Derivative instruments	(28)		54
Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Derivative instruments	287		213
Swap associated with the sale of Visa, Inc. Class B shares | Fair value, recurring
Quantitative information about level 3 fair value measurements
Derivative instruments	$ (37)		$ (29)
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	(22.10%)		(90.80%)
Credit risk factor	0.00%		2.20%
Minimum | IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Loan closing rates	9.90%		9.90%
Minimum | Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Expected term (years)	2 years		1 year 9 months
Expected volatility	23.80%	[1]	29.00%	[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	3/31/2014		6/30/2013
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	45.60%		16.50%
Credit risk factor	67.00%		68.40%
Maximum | IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Loan closing rates	95.00%		86.90%
Maximum | Stock warrants associated with Vantiv Holding, LLC | Fair value, recurring
Quantitative information about level 3 fair value measurements
Expected term (years)	16 years		17 years
Expected volatility	34.70%	[1]	41.20%	[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	3/31/2017		6/30/2015
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	3.80%		5.50%
Credit risk factor	3.30%		4.40%
Weighted average | IRLCs, net | Fair value, recurring
Quantitative information about level 3 fair value measurements
Loan closing rates	63.00%		54.00%
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		4 years 9 months 18 days
Expected volatility	28.90%	[1]	35.40%	[1]
Fixed | Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Prepayment speed	11.80%		15.20%
Discount rate	10.40%		10.60%
Adjustable | Servicing Rights | Fair value, nonrecurring
Quantitative information about level 3 fair value measurements
Prepayment speed	25.90%		27.10%
Discount rate	11.60%		11.70%

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