Certain Transfers of Financial Assets and Variable Interest Entities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended					3 Months Ended			3 Months Ended	12 Months Ended																					3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013		Mar. 31, 2014 Affordable Housing Investment [Member]	Mar. 31, 2014 Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2013 Variable Interest Entity, Primary Beneficiary [Member]	Mar. 31, 2014 Residential Mortgage Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Residential Mortgage Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Preference Shares [Member]	Dec. 31, 2013 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Preference Shares [Member]	Mar. 31, 2014 Commercial and Corporate Loans [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2013 Commercial and Corporate Loans [Member] Variable Interest Entity, Primary Beneficiary [Member]	Mar. 31, 2014 Student Loans [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2013 Student Loans [Member] Variable Interest Entity, Primary Beneficiary [Member]	Mar. 31, 2014 Student Loans [Member] Variable Interest Entity, Primary Beneficiary [Member] Maximum [Member]	Dec. 31, 2013 Student Loans [Member] Variable Interest Entity, Primary Beneficiary [Member] Maximum [Member]	Mar. 31, 2014 Total Return Swap Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Total Return Swap Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Ridgeworth Capital Management [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Ridgeworth Capital Management [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Limited Partner [Member] Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Limited Partner [Member] Community Development Investments [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Partnership [Member] Community Development Investments [Member]	Dec. 31, 2013 Partnership [Member] Community Development Investments [Member]	Mar. 31, 2014 provision for income taxes [Member]	Mar. 31, 2013 provision for income taxes [Member]	Mar. 31, 2014 Portion at Fair Value Measurement [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2013 Portion at Fair Value Measurement [Member] Variable Interest Entity, Primary Beneficiary [Member]
Loans and Leases Receivable, Gain (Loss) on Sales, Net									$ 43	$ 157
Transferor's Interests in Transferred Financial Assets, Fair Value									70	71
Total assets	179,542			175,335					336	350	1,700	1,600	3	3									1,400	1,500	230	247			110	151
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]						65
Loans Receivable Held-for-sale, Net	1,488	[1]		1,699	[1]																												224	261
Long-term Debt	11,565	[2]		10,700	[2]		570	597							238	256	332	341
Total liabilities	157,725			153,913							1,600	1,600																	56	58
Loans Receivable, Net																	336	344
Government guaranteed percent																			97.00%	97.00%
Trading assets	4,848			5,040																	1,400	1,500
Derivative, Notional Amount																					1,400	1,500
Derivative Asset, Fair Value, Gross Asset	5,463			6,125																	25	35
Derivative Liability, Fair Value, Gross Liability	5,139			5,673																	21	31
Other Assets	5,481			5,520																			150	138			249	252
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount																							241	217			725	697
Loans issued by the Company to the limited partnerships																											328	303
Investment Tax Credit	15		15
Other Depreciation and Amortization																															13	10
Noninterest Income	791		863
Gain (Loss) on Sale of Properties						$ (36)

[1] Includes loans held for sale, at fair value, of consolidated VIEs of $224 million and $261 million at March 31, 2014 and December 31, 2013, respectively.

[2] Includes debt of consolidated VIEs of $570 million and $597 million at March 31, 2014 and December 31, 2013, respectively, of which $238 and $256 are carried at fair value at March 31, 2014 and December 31, 2013, respectively.