Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Cash and due from banks, interest-bearing amounts	$ 57,048us-gaap_InterestBearingDepositsInBanks	$ 53,594us-gaap_InterestBearingDepositsInBanks
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50
Common stock, shares authorized	50,000,000us-gaap_CommonStockSharesAuthorized	50,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	31,197,365us-gaap_CommonStockSharesIssued	31,197,365us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	29,796,397us-gaap_CommonStockSharesOutstanding	29,737,725us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	1,400,968us-gaap_TreasuryStockShares	1,459,640us-gaap_TreasuryStockShares

Face amount or stated value per share of common stock.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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