Certain Transfers of Financial Assets and Variable Interest Entities - Additional Information (Detail) (USD $)	12 Months Ended							12 Months Ended																		12 Months Ended							12 Months Ended				12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2012 Variable Interest Entity, Primary Beneficiary	Dec. 31, 2011 Variable Interest Entity, Primary Beneficiary	Dec. 31, 2012 Residential Mortgage Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Residential Mortgage Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2010 Residential Mortgage Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2012 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2012 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Preference Shares	Dec. 31, 2011 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Preference Shares	Dec. 31, 2012 Commercial and Corporate Loans [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2011 Commercial and Corporate Loans [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2012 Student Loans [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2011 Student Loans [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2012 Student Loans [Member] Variable Interest Entity, Primary Beneficiary Upper Limit	Dec. 31, 2011 Student Loans [Member] Variable Interest Entity, Primary Beneficiary Upper Limit	Dec. 31, 2012 Collateralized Debt Obligations [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Collateralized Debt Obligations [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2012 Collateralized Debt Obligations [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Trading Assets [Member]	Dec. 31, 2011 Collateralized Debt Obligations [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Trading Assets [Member]	Dec. 31, 2012 Collateralized Debt Obligations [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Lower Limit	Dec. 31, 2012 Three Pillars [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2011 Three Pillars [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2010 Three Pillars [Member] Variable Interest Entity, Primary Beneficiary	Dec. 31, 2011 Three Pillars [Member] Variable Interest Entity, Primary Beneficiary Commercial Portfolio Segment [Member]	Mar. 31, 2010 Three Pillars [Member] Variable Interest Entity, Primary Beneficiary Commercial Portfolio Segment [Member]	Dec. 31, 2012 Total Return Swap Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Total Return Swap Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2012 Community Development Investments [Member]	Dec. 31, 2011 Community Development Investments [Member]	Dec. 31, 2012 Community Development Investments [Member] General Partner [Member]	Dec. 31, 2011 Community Development Investments [Member] General Partner [Member]	Dec. 31, 2012 Community Development Investments [Member] Partnership [Member]	Dec. 31, 2011 Community Development Investments [Member] Partnership [Member]	Dec. 31, 2012 Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2012 Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Limited Partner	Dec. 31, 2011 Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Limited Partner	Dec. 31, 2012 Ridgeworth Fund Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2011 Ridgeworth Fund Variable Interest Entity, Not Primary Beneficiary [Member]
Loans and Leases Receivable, Gain (Loss) on Sales, Net								$ 1,000,000,000	$ 397,000,000	$ 588,000,000
Transferor's Interests in Transferred Financial Assets, Fair Value								98,000,000	104,000,000														52,000,000	43,000,000
Total assets	173,442,000,000		176,859,000,000					445,000,000	529,000,000		1,800,000,000	2,000,000,000	3,000,000	2,000,000							1,200,000,000	1,200,000,000							2,900,000,000						3,000,000	5,000,000	239,000,000	360,000,000	1,200,000,000	1,200,000,000			372,000,000	1,100,000,000
Loans Receivable Held-for-sale, Net	3,399,000,000	[1]	2,353,000,000			319,000,000	315,000,000
Long-term Debt	9,357,000,000	[2]	10,908,000,000	[2]		666,000,000	722,000,000								286,000,000	289,000,000	380,000,000	433,000,000
Loans Receivable, Net																315,000,000	384,000,000	438,000,000
Total liabilities	152,457,000,000		156,793,000,000								1,700,000,000	1,900,000,000																							1,000,000	1,000,000	100,000,000	107,000,000
Government guaranteed percent																			97.00%	97.00%
Declines in fair values for the total retained interests due to 20% adverse changes in the discount rate																					19,000,000				7,000,000
Allowance for loan losses on consolidated loans																														1,700,000,000
Total Fee Revenue																										11,000,000	65,000,000	68,000,000
Senior financing outstanding to VIEs																															1,900,000,000	1,700,000,000
VIEs had entered into TRS contracts with the Company with outstanding notional amounts																															1,900,000,000	1,600,000,000
Derivative asset positions																															51,000,000	20,000,000
Derivative Liability, Fair Value, Gross Liability																															46,000,000	17,000,000
Other assets	5,335,000,000		6,159,000,000																																				63,000,000	68,000,000	186,000,000	194,000,000
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount																																							110,000,000	108,000,000	505,000,000	472,000,000
Loans issued by the Company to the limited partnerships																																									236,000,000	249,000,000
Valuation losses on affordable housing investments	96,000,000		10,000,000		15,000,000																												96,000,000	10,000,000	3,000,000		93,000,000
Balance of Affordable Housing Properties Held for sale	$ 100,000,000

[1] 1 Includes loans held for sale, at fair value, of consolidated VIEs319 315

[2] 3 Includes debt of consolidated VIEs ($286 and $289 at fair value as of December 31, 2012 and December 31, 2011, respectively)666 722