Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Available for sale:
Amortized Cost	$ 292,205	$ 279,209
Estimated Fair Value	307,719	299,204
Gross Unrealized Gains	16,195	21,148
Gross Unrealized Losses	(681)	(1,153)
Held to maturity:
Estimated Fair Value	8,920	10,161
Total Amortized Cost	300,300	288,524
Total Fair Value	316,639	309,365
Total gross unrealized gains	17,020	21,994
Total gross unrealized losses	(681)	(1,153)
U.S. Government Agency Securities [Member]
Available for sale:
Amortized Cost	5,043
Estimated Fair Value	5,034
Gross Unrealized Losses	(9)
Obligations of states and political subdivisions [Member]
Available for sale:
Amortized Cost	156,216	156,663
Estimated Fair Value	167,589	171,992
Gross Unrealized Gains	11,376	15,329
Gross Unrealized Losses	(3)
Held to maturity:
Estimated Fair Value	8,920	10,161
Amortized Cost	8,095	9,315
Gross Unrealized Gains	825	846
Gross Unrealized Losses
Collateralized Mortgage Obligations [Member]
Available for sale:
Amortized Cost	106,730	122,155
Estimated Fair Value	110,814	126,770
Gross Unrealized Gains	4,749	5,768
Gross Unrealized Losses	(665)	(1,153)
Mortgage-backed securities [Member]
Available for sale:
Amortized Cost	16,908	391
Estimated Fair Value	16,927	442
Gross Unrealized Gains	21	51
Gross Unrealized Losses	(2)
Corporate Bonds [Member]
Available for sale:
Amortized Cost	7,308
Estimated Fair Value	7,355
Gross Unrealized Gains	49
Gross Unrealized Losses	$ (2)

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