Fair Value Disclosures (Financial Instruments Carrying Value And Estimated Fair Value) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 127,174	$ 124,177	$ 91,492
Federal funds sold	3,580		6,135
Interest-bearing deposits in banks	170,538	243,776	231,532
Held to maturity securities	4,362	9,064	9,229
Available for sale securities	1,728,557	1,537,178	1,412,173
Loans	1,694,531	1,659,240	1,507,695
Short term borrowings	180,790	178,356	178,097
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	127,174	124,177
Federal funds sold	3,580
Interest-bearing deposits in banks	170,538	243,776
Held to maturity securities	4,362	9,064
Available for sale securities	1,728,557	1,537,178
Loans	1,694,531	1,659,240
Accrued interest receivable	19,430	21,006
Deposits with stated maturities	768,758	837,615
Deposits with no stated maturities	2,417,848	2,275,686
Short term borrowings	180,790	178,356
Accrued interest payable	592	1,234
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	127,174	124,177
Federal funds sold	3,580
Interest-bearing deposits in banks	170,538	243,776
Held to maturity securities	4,424	9,240
Available for sale securities	1,728,557	1,537,178
Loans	1,694,868	1,659,444
Accrued interest receivable	19,430	21,006
Deposits with stated maturities	770,241	840,234
Deposits with no stated maturities	2,417,848	2,275,686
Short term borrowings	180,790	178,356
Accrued interest payable	$ 592	$ 1,234

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The amount outstanding of funds lent to other depository institutions, securities brokers, or securities dealers in the form of Federal Funds sold; for example, immediately available funds lent under agreements or contracts that mature in one business day or roll over under a continuing contract, regardless of the nature of the transaction or the collateral involved, excluding overnight lending for commercial and industrial purposes. Also include Federal Funds sold under agreements to resell on a gross basis, excluding (1) sales of term Federal Funds, (2) due bills representing purchases of securities or other assets by the reporting bank that have not yet been delivered and similar instruments, (3) resale agreements that mature in more than one business day involving assets other than securities, and (4) yield maintenance dollar repurchase agreements.

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