Investment Securities - Amortized Cost and Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities
Amortized Cost, Total available-for-sale securities	$ 332,259	$ 324,172
Unrealized Gains	7,853	7,372
Unrealized Losses	640	1,122
Fair Value, Total available-for-sale securities	339,472	330,422	[1]
Securities of U.S. government agencies
Schedule of Available-for-sale Securities
Amortized Cost, Within 1 year	20,010	9,988
Amortized Cost, After 1 but within 5 years	2,974	13,622
Amortized Cost	22,984	23,610
Unrealized Gains	75	116
Unrealized Losses	0	0
Fair Value, Within 1 year	20,078	10,039
Fair Value, After 1 but within 5 years	2,981	13,687
Fair Value	23,059	23,726
Government sponsored agencies - Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Amortized Cost, Within 1 year	102
Amortized Cost, After 1 but within 5 years	598	476
Amortized Cost, After 5 but within 10 years	2,380	3,481
Amortized Cost, After 10 years	75,759	60,388
Amortized Cost	78,839	64,345
Unrealized Gains	1,655	1,258
Unrealized Losses	35	393
Fair Value, Within 1 year	104
Fair Value, After 1 but within 5 years	627	494
Fair Value, After 5 but within 10 years	2,586	3,762
Fair Value, After 10 years	77,142	60,954
Fair Value	80,459	65,210
Government sponsored agencies - Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Amortized Cost, After 1 but within 5 years	3,489
Amortized Cost, After 5 but within 10 years	9,001	13,986
Amortized Cost, After 10 years	153,503	150,915
Amortized Cost	165,993	164,901
Unrealized Gains	1,633	1,719
Unrealized Losses	561	592
Fair Value, After 1 but within 5 years	3,507
Fair Value, After 5 but within 10 years	9,270	14,464
Fair Value, After 10 years	154,288	151,564
Fair Value	167,065	166,028
Private label collateralized mortgage obligations
Schedule of Available-for-sale Securities
Amortized Cost, After 5 but within 10 years	229	275
Amortized Cost, After 10 years	925	1,028
Amortized Cost	1,154	1,303
Unrealized Gains	0	10
Unrealized Losses	5	57
Fair Value, After 5 but within 10 years	228	285
Fair Value, After 10 years	921	971
Fair Value	1,149	1,256
State and municipal securities
Schedule of Available-for-sale Securities
Amortized Cost, Within 1 year	720	618
Amortized Cost, After 1 but within 5 years	5,425	6,575
Amortized Cost, After 5 but within 10 years	19,631	21,252
Amortized Cost, After 10 years	36,399	40,455
Amortized Cost	62,175	68,900
Unrealized Gains	4,432	4,246
Unrealized Losses	0	28
Fair Value, Within 1 year	736	623
Fair Value, After 1 but within 5 years	5,792	6,922
Fair Value, After 5 but within 10 years	21,040	22,872
Fair Value, After 10 years	39,039	42,701
Fair Value	66,607	73,118
Common and preferred stocks
Schedule of Available-for-sale Securities
Amortized Cost, Common and preferred stocks	1,114	1,113
Unrealized Gains	58	23
Unrealized Losses	39	52
Fair Value, Common and preferred stocks	1,133	1,084
Within 1 year | Securities of U.S. government agencies
Schedule of Available-for-sale Securities
Unrealized Gains	68	51
Unrealized Losses	0	0
Within 1 year | Government sponsored agencies - Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Unrealized Gains	2
Unrealized Losses	0
Within 1 year | State and municipal securities
Schedule of Available-for-sale Securities
Unrealized Gains	16	5
Unrealized Losses	0	0
After 1 but within 5 years | Securities of U.S. government agencies
Schedule of Available-for-sale Securities
Unrealized Gains	7	65
Unrealized Losses	0	0
After 1 but within 5 years | Government sponsored agencies - Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Unrealized Gains	29	18
Unrealized Losses	0	0
After 1 but within 5 years | Government sponsored agencies - Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Unrealized Gains	18
Unrealized Losses	0
After 1 but within 5 years | State and municipal securities
Schedule of Available-for-sale Securities
Unrealized Gains	367	347
Unrealized Losses	0	0
After 5 but within 10 years | Government sponsored agencies - Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Unrealized Gains	206	281
Unrealized Losses	0	0
After 5 but within 10 years | Government sponsored agencies - Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Unrealized Gains	269	478
Unrealized Losses	0	0
After 5 but within 10 years | Private label collateralized mortgage obligations
Schedule of Available-for-sale Securities
Unrealized Gains	0	10
Unrealized Losses	1	0
After 5 but within 10 years | State and municipal securities
Schedule of Available-for-sale Securities
Unrealized Gains	1,409	1,639
Unrealized Losses	0	19
After 10 years | Government sponsored agencies - Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Unrealized Gains	1,418	959
Unrealized Losses	35	393
After 10 years | Government sponsored agencies - Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Unrealized Gains	1,346	1,241
Unrealized Losses	561	592
After 10 years | Private label collateralized mortgage obligations
Schedule of Available-for-sale Securities
Unrealized Gains	0	0
Unrealized Losses	4	57
After 10 years | State and municipal securities
Schedule of Available-for-sale Securities
Unrealized Gains	2,640	2,255
Unrealized Losses	$ 0	$ 9

[1] Derived from audited consolidated financial statements