Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment Securities:
Available-for-sale Securities Pledged as Collateral	$ 468,843	$ 467,143
Stockholders' Equity:
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	2,000,000us-gaap_PreferredStockSharesAuthorized	2,000,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, shares issued	6,000us-gaap_PreferredStockSharesIssued	6,000us-gaap_PreferredStockSharesIssued
Common stock, par value	$ 5.00	$ 5.00
Common Stock, Shares Authorized	120,000,000us-gaap_CommonStockSharesAuthorized	120,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	96,830,977us-gaap_CommonStockSharesIssued	96,830,977us-gaap_CommonStockSharesIssued
Treasury stock, shares	154,567us-gaap_TreasuryStockShares	367,487us-gaap_TreasuryStockShares

The fair value of available-for-sale securities that serve as collateral for borrowings.

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