Securities (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Other government agencies [Member]
Schedule of unrealized losses on investment securities
Less than 12 months, Fair Value	$ 8,047	$ 18,894
Less than 12 months, Unrealized Losses	(4)	(56)
Less than 12 months, Number of Securities	3	6
12 months or more, Fair Value	4,664
12 months or more, Unrealized Losses	(27)
12 months or more, Number of Securities	1
Fair Value, Total	12,711	18,894
Unrealized Losses, Total	(31)	(56)
Number of Securities Total	4	6
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies [Member]
Schedule of unrealized losses on investment securities
Less than 12 months, Fair Value	93,980	38,913
Less than 12 months, Unrealized Losses	(502)	(258)
Less than 12 months, Number of Securities	18	20
12 months or more, Fair Value	7,294	9,966
12 months or more, Unrealized Losses	(94)	(126)
12 months or more, Number of Securities	8	10
Fair Value, Total	101,274	48,879
Unrealized Losses, Total	(596)	(384)
Number of Securities Total	26	30
Obligations of state and political subdivisions [Member]
Schedule of unrealized losses on investment securities
Less than 12 months, Fair Value	97,422	72,521
Less than 12 months, Unrealized Losses	(1,736)	(838)
Less than 12 months, Number of Securities	145	107
12 months or more, Fair Value	3,999
12 months or more, Unrealized Losses	(104)
12 months or more, Number of Securities	3
Fair Value, Total	101,421	72,521
Unrealized Losses, Total	(1,840)	(838)
Number of Securities Total	148	107
Corporate debt securities [Member]
Schedule of unrealized losses on investment securities
Less than 12 months, Fair Value	1,980	1,526
Less than 12 months, Unrealized Losses	(3)	(57)
Less than 12 months, Number of Securities	1	2
12 months or more, Fair Value	7,941	10,878
12 months or more, Unrealized Losses	(59)	(177)
12 months or more, Number of Securities	3	5
Fair Value, Total	9,921	12,404
Unrealized Losses, Total	(62)	(234)
Number of Securities Total	4	7
Equity securities [Member]
Schedule of unrealized losses on investment securities
Less than 12 months, Fair Value	2,848	2,838
Less than 12 months, Unrealized Losses	(40)	(21)
Less than 12 months, Number of Securities	2	2
12 months or more, Fair Value
12 months or more, Unrealized Losses
12 months or more, Number of Securities
Fair Value, Total	2,848	2,838
Unrealized Losses, Total	(40)	(21)
Number of Securities Total	2	2
Total temporarily impaired securities [Member]
Schedule of unrealized losses on investment securities
Less than 12 months, Fair Value	204,277	134,692
Less than 12 months, Unrealized Losses	(2,285)	(1,230)
Less than 12 months, Number of Securities	169	137
12 months or more, Fair Value	23,898	20,844
12 months or more, Unrealized Losses	(284)	(303)
12 months or more, Number of Securities	15	15
Fair Value, Total	228,175	155,536
Unrealized Losses, Total	$ (2,569)	$ (1,533)
Number of Securities Total	184	152