Certain Transfers of Financial Assets and Variable Interest Entities - Additional Information (Detail) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012	Dec. 31, 2012
Total assets	$ 171,546,000,000			$ 171,546,000,000			$ 173,442,000,000
Loans Receivable Held-for-sale, Net	3,647,000,000	[1]		3,647,000,000	[1]		3,399,000,000
Long-term Debt	9,818,000,000	[2]		9,818,000,000	[2]		9,357,000,000	[2]
Total liabilities	150,539,000,000			150,539,000,000			152,457,000,000
Derivative Asset, Fair Value, Gross Asset	6,621,000,000			6,621,000,000			8,656,000,000
Derivative Liability, Fair Value, Gross Liability	5,938,000,000			5,938,000,000			7,514,000,000
Other Assets	5,304,000,000			5,304,000,000			5,335,000,000
Variable Interest Entity, Primary Beneficiary
Loans Receivable Held-for-sale, Net	289,000,000			289,000,000			319,000,000
Long-term Debt	645,000,000			645,000,000			666,000,000
Residential Mortgage | Variable Interest Entity, Not Primary Beneficiary [Member]
Loans and Leases Receivable, Gain (Loss) on Sales, Net	124,000,000		236,000,000	281,000,000		460,000,000
Transferor's Interests in Transferred Financial Assets, Fair Value	83,000,000			83,000,000			98,000,000
Total assets	390,000,000			390,000,000			445,000,000
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Total assets	1,700,000,000			1,700,000,000			1,800,000,000
Total liabilities	1,700,000,000			1,700,000,000			1,700,000,000
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Preference Shares
Total assets	3,000,000			3,000,000			3,000,000
Commercial and Corporate Loans [Member] | Variable Interest Entity, Primary Beneficiary
Long-term Debt	285,000,000			285,000,000			286,000,000
Student Loans [Member] | Variable Interest Entity, Primary Beneficiary
Long-term Debt	360,000,000			360,000,000			380,000,000
Loans Receivable, Net	364,000,000			364,000,000			384,000,000
Student Loans [Member] | Variable Interest Entity, Primary Beneficiary | Upper Limit
Government guaranteed percent	97.00%			97.00%			97.00%
Collateralized Debt Obligations [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Total assets	1,100,000,000			1,100,000,000			1,200,000,000
Declines in fair values for the total retained interests due to 20% adverse changes in the discount rate	13,000,000			13,000,000
Collateralized Debt Obligations [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Trading Assets [Member]
Transferor's Interests in Transferred Financial Assets, Fair Value	62,000,000			62,000,000			52,000,000
CDO Securities Weighted Average Expected Maturity in Years				21 years
Collateralized Debt Obligations [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Upper Limit | Trading Assets [Member]
Fair Value Inputs, Market Yield				12.00%
Collateralized Debt Obligations [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Lower Limit
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Other Assumption	6,000,000			6,000,000
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Adverse Change in Other Assumption	11,000,000			11,000,000
Collateralized Debt Obligations [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Lower Limit | Trading Assets [Member]
Fair Value Inputs, Market Yield				9.50%
Total Return Swap | Variable Interest Entity, Not Primary Beneficiary [Member]
Senior financing outstanding to VIEs	1,800,000,000			1,800,000,000			1,900,000,000
VIEs had entered into TRS contracts with the Company with outstanding notional amounts	1,800,000,000			1,800,000,000			1,900,000,000
Derivative Asset, Fair Value, Gross Asset	30,000,000			30,000,000			51,000,000
Derivative Liability, Fair Value, Gross Liability	26,000,000			26,000,000			46,000,000
Community Development Investments [Member] | General Partner [Member]
Total assets	3,000,000			3,000,000			3,000,000
Total liabilities	1,000,000			1,000,000			1,000,000
Community Development Investments [Member] | Partnership [Member]
Total assets	229,000,000			229,000,000			239,000,000
Total liabilities	95,000,000			95,000,000			100,000,000
Community Development Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Total assets	1,200,000,000			1,200,000,000			1,200,000,000
Other Assets	71,000,000			71,000,000			63,000,000
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	157,000,000			157,000,000			110,000,000
Community Development Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Limited Partner
Other Assets	206,000,000			206,000,000			186,000,000
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	541,000,000			541,000,000			505,000,000
Loans issued by the Company to the limited partnerships	266,000,000			266,000,000			236,000,000
Ridgeworth Fund | Variable Interest Entity, Not Primary Beneficiary [Member]
Total assets	$ 301,000,000			$ 301,000,000			$ 372,000,000

[1] 1 Includes loans held for sale, at fair value, of consolidated VIEs$289 $319

[2] 3 Includes debt of consolidated VIEs ($285 and $286 at fair value at June 30, 2013 and December 31, 2012, respectively)645 666