Loans (Investment in Loans Related to the Allowance for Loan Losses) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010
Commercial and Industrial	$ 3,842,150	$ 3,788,658	$ 3,690,072
Commercial Real Estate	3,157,099	3,202,767	3,194,598
Consumer Real Estate	773,069	798,264	811,954
Consumer and Other	314,305	347,618	391,130
Unearned discounts	(18,411)	(20,287)	(22,075)
Total loans	8,068,212	8,117,020	8,065,679
Loans Individually Evaluated for Impairment [Member]
Commercial and Industrial	245,665	314,482	339,000
Commercial Real Estate	279,486	337,578	373,798
Consumer Real Estate	416
Total loans	525,567	652,060	712,798
Loans Collectively Evaluated for Impairment [Member]
Commercial and Industrial	3,596,485	3,474,176	3,351,072
Commercial Real Estate	2,877,613	2,865,189	2,820,800
Consumer Real Estate	772,653	798,264	811,954
Consumer and Other	314,305	347,618	391,130
Unearned discounts	(18,411)	(20,287)	(22,075)
Total loans	$ 7,542,645	$ 7,464,960	$ 7,352,881

Unearned discounts

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- Definition

The total value of other non major installment loans (gross) made by financial institutions to consumers, the proceeds of which are used by individuals (borrowers) for purchases such as household goods, vacations, and other consumer items. Such loans should be repaid in periodic payments over a predetermined time period, are generally secured by the item purchased and may be either direct to the borrower (direct paper) or to the dealer (indirect paper or retail sales contract).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph e

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Subparagraph a, b
-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 8
-Subparagraph b(iii)
-Subsection I

+ Details

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- Definition

The total gross amount of money lent to individual customers including construction financing, residential mortgage loans, and home equity lines of credit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-DEP
-Chapter 8
-Paragraph 40-43
-IssueDate 2006-05-01

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph e

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Subparagraph a, b
-Article 9

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 8
-Subparagraph c(i)
-Subsection I

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Reflects the aggregate gross carrying amount of all categories of loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on loans and leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph e

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-DEP
-Chapter 8
-Paragraph 116
-IssueDate 2006-05-01

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 8
-Subparagraph e
-Subsection I

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Reflects the gross carrying amount of unpaid loans issued to nonfinancial and nonagricultural businesses for uses other than for real property.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph e

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 8
-Subparagraph b(iv)
-Subsection I

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Subparagraph a(1)
-Article 9

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the sum of the gross carrying amounts of unpaid loans issued to businesses to acquire, develop, construct, improve, or refinance land or a building. Includes [but is not limited to] commercial mortgage loans, which are secured by a [legal] security interest in real property [commercial building or business real property] which thereby serves as collateral securing repayment of the loan; and construction financing, which is an obligation generally in the form of a [promissory] note, used for the funding of construction projects.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-DEP
-Chapter 8
-Paragraph 51, 52, 53
-IssueDate 2006-05-01

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 13
-Subparagraph e

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 60
-Paragraph 47

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Subparagraph a
-Article 9

+ Details

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