Changes in the Net Carrying Amount of Goodwill by Reporting Segment (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended
Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2012 Commercial Banking [Member]	Dec. 31, 2011 Commercial Banking [Member]	Dec. 31, 2010 Commercial Banking [Member]	Dec. 31, 2012 Branch Banking [Member]	Dec. 31, 2010 Branch Banking [Member]	Dec. 31, 2012 Investment Advisors [Member]	Dec. 31, 2011 Investment Advisors [Member]	Dec. 31, 2010 Investment Advisors [Member]
GoodwillRollForward
Net carrying value, beginning of period:	$ 2,417	$ 2,417	$ 613	$ 613	$ 613	$ 1,656	$ 1,656	$ 148	$ 148	$ 148
Purchase accounting adjustments	(1)					(1)
Net carrying value, end of period:	$ 2,416	$ 2,417	$ 613	$ 613	$ 613	$ 1,655	$ 1,656	$ 148	$ 148	$ 148

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 45

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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