Goodwill and Other Intangible Assets (Details Textuals) (USD $)	9 Months Ended	12 Months Ended
Sep. 30, 2011	Dec. 31, 2010
Goodwill [Line Items]
Goodwill	$ 929,168,000	$ 929,168,000
Goodwill and Other Intangible Assets (Textuals) [Abstract]
Amortization of other intangible assets	1,200,000	1,200,000
Banking segment [Member]
Goodwill [Line Items]
Goodwill	907,000,000	907,000,000
Wealth segment [Member]
Goodwill [Line Items]
Goodwill	$ 22,000,000	$ 22,000,000

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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-Name Statement of Financial Accounting Standard (FAS)

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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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 3: 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details