Loans and Allowance for Credit Losses Summary Of Gross Loans (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Loans [Line Items]
Loans, gross of unearned income	$ 12,384,755	$ 12,154,209
Unearned income	(7,467)	(7,238)
Loans, net of unearned income	12,377,288	12,146,971	11,960,004
Real-estate commercial mortage [Member]
Loans [Line Items]
Loans, gross of unearned income	4,729,930	4,664,426
Loans, net of unearned income	4,729,930		4,634,428
Commercial - industrial, financial, and agricultural
Loans [Line Items]
Loans, gross of unearned income	3,658,483	3,612,065
Loans, net of unearned income	3,658,483		3,518,228
Real-estate - home equity [Member]
Loans [Line Items]
Loans, gross of unearned income	1,689,446	1,632,390
Loans, net of unearned income	1,689,446		1,601,880
Real-estate - residential mortgage [Member]
Loans [Line Items]
Loans, gross of unearned income	1,303,454	1,257,432
Loans, net of unearned income	1,303,454		1,177,474
Real-estate - construction
Loans [Line Items]
Loans, gross of unearned income	597,597	584,118
Loans, net of unearned income	597,597		647,700
Consumer
Loans [Line Items]
Loans, gross of unearned income	309,138	309,864
Loans, net of unearned income	309,138		309,168
Leasing and other [Member]
Loans [Line Items]
Loans, gross of unearned income	78,801	75,521
Overdrafts [Member]
Loans [Line Items]
Loans, gross of unearned income	$ 17,906	$ 18,393

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(i-v)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 01-6

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph f

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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

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

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-Name Accounting Standards Codification

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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph e

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It 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)

-Number 13

-Paragraph 23

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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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details