Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Available for sale (AFS)
Amortized Cost	$ 310,856	$ 273,916
Gross Unrealized Gains	7,929	17,153
Gross Unrealized Losses	(7,496)	(1,753)
Fair Value	311,289	289,316
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	118,055	21,809
Gross Unrealized Losses, Less than Twelve Months	(5,802)	(553)
Fair value, Twelve Months or Greater	5,118	9,642
Gross Unrealized Losses, Twelve Months or Greater	(1,694)	(1,200)
Fair Value, Total	123,173	31,451
Gross Unrealized Losses, Total	(7,496)	(1,753)
Debt securities
Available for sale (AFS)
Amortized Cost	300,274	263,426
Gross Unrealized Gains	6,414	15,939
Gross Unrealized Losses	(7,459)	(1,702)
Fair Value	299,229	277,663
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	117,316	21,042
Gross Unrealized Losses, Less than Twelve Months	(5,769)	(524)
Fair value, Twelve Months or Greater	5,055	9,374
Gross Unrealized Losses, Twelve Months or Greater	(1,690)	(1,178)
Fair Value, Total	122,371	30,416
Gross Unrealized Losses, Total	(7,459)	(1,702)
U.S. Government and agency securities
Available for sale (AFS)
Amortized Cost	31,937	24,475
Gross Unrealized Gains	870	1,384
Gross Unrealized Losses	(293)	(19)
Fair Value	32,514	25,840
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	15,150	910
Gross Unrealized Losses, Less than Twelve Months	(293)	(19)
Fair Value, Total	15,150	910
Gross Unrealized Losses, Total	(293)	(19)
State and political securities
Available for sale (AFS)
Amortized Cost	164,477	168,843
Gross Unrealized Gains	4,611	12,805
Gross Unrealized Losses	(4,687)	(1,424)
Fair Value	164,401	180,224
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	41,588	8,882
Gross Unrealized Losses, Less than Twelve Months	(3,019)	(316)
Fair value, Twelve Months or Greater	4,327	5,647
Gross Unrealized Losses, Twelve Months or Greater	(1,668)	(1,108)
Fair Value, Total	45,915	14,529
Gross Unrealized Losses, Total	(4,687)	(1,424)
Other debt securities
Available for sale (AFS)
Amortized Cost	103,860	70,108
Gross Unrealized Gains	933	1,750
Gross Unrealized Losses	(2,479)	(259)
Fair Value	102,314	71,599
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	60,578	11,250
Gross Unrealized Losses, Less than Twelve Months	(2,457)	(189)
Fair value, Twelve Months or Greater	728	3,727
Gross Unrealized Losses, Twelve Months or Greater	(22)	(70)
Fair Value, Total	61,306	14,977
Gross Unrealized Losses, Total	(2,479)	(259)
Equity securities
Available for sale (AFS)
Amortized Cost	10,582	10,490
Gross Unrealized Gains	1,515	1,214
Gross Unrealized Losses	(37)	(51)
Fair Value	12,060	11,653
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	739	767
Gross Unrealized Losses, Less than Twelve Months	(33)	(29)
Fair value, Twelve Months or Greater	63	268
Gross Unrealized Losses, Twelve Months or Greater	(4)	(22)
Fair Value, Total	802	1,035
Gross Unrealized Losses, Total	(37)	(51)
Financial institution equity securities
Available for sale (AFS)
Amortized Cost	9,810	8,422
Gross Unrealized Gains	1,515	1,140
Gross Unrealized Losses	(4)	(14)
Fair Value	11,321	9,548
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months		66
Gross Unrealized Losses, Less than Twelve Months		(1)
Fair value, Twelve Months or Greater	63	205
Gross Unrealized Losses, Twelve Months or Greater	(4)	(13)
Fair Value, Total	63	271
Gross Unrealized Losses, Total	(4)	(14)
Other equity securities
Available for sale (AFS)
Amortized Cost	772	2,068
Gross Unrealized Gains		74
Gross Unrealized Losses	(33)	(37)
Fair Value	739	2,105
Gross unrealized losses and fair value
Fair Value, Less than Twelve Months	739	701
Gross Unrealized Losses, Less than Twelve Months	(33)	(28)
Fair value, Twelve Months or Greater		63
Gross Unrealized Losses, Twelve Months or Greater		(9)
Fair Value, Total	739	764
Gross Unrealized Losses, Total	$ (33)	$ (37)