Investment Securities - Investments in continuous loss position (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities
Less Than 12 Months, Fair value	$ 136,236	$ 64,766
Less Than 12 Months, Unrealized losses	6,639	826
12 Months or More, Fair value	165	7,864
12 Months or More, Unrealized losses	1	169
Total, Fair value	136,401	72,630
Total, Unrealized losses	6,640	995
U.S. government agencies
Schedule of Available-for-sale Securities
Less Than 12 Months, Fair value	16,625	2,429
Less Than 12 Months, Unrealized losses	312	1
12 Months or More, Fair value	0	0
12 Months or More, Unrealized losses	0	0
Total, Fair value	16,625	2,429
Total, Unrealized losses	312	1
Government sponsored agencies - Residential mortgage-backed securities
Schedule of Available-for-sale Securities
Less Than 12 Months, Fair value	32,615	12,021
Less Than 12 Months, Unrealized losses	1,150	325
12 Months or More, Fair value	0	0
12 Months or More, Unrealized losses	0	0
Total, Fair value	32,615	12,021
Total, Unrealized losses	1,150	325
Government sponsored agencies - Collateralized mortgage obligations
Schedule of Available-for-sale Securities
Continuous unrealized loss investments, number of positions		3
Less Than 12 Months, Fair value	15,580	27,417
Less Than 12 Months, Unrealized losses	136	127
12 Months or More, Fair value	0	7,626
12 Months or More, Unrealized losses	0	168
Total, Fair value	15,580	35,043
Total, Unrealized losses	136	295
Private label collateralized mortgage obligations
Schedule of Available-for-sale Securities
Continuous unrealized loss investments, number of positions	1	1
Less Than 12 Months, Fair value	6,725	0
Less Than 12 Months, Unrealized losses	132	0
12 Months or More, Fair value	165	178
12 Months or More, Unrealized losses	1	0
Total, Fair value	6,890	178
Total, Unrealized losses	133	0
State and municipal securities
Schedule of Available-for-sale Securities
Less Than 12 Months, Fair value	64,691	22,899
Less Than 12 Months, Unrealized losses	4,909	373
12 Months or More, Fair value	0	0
12 Months or More, Unrealized losses	0	0
Total, Fair value	64,691	22,899
Total, Unrealized losses	4,909	373
Common and preferred stocks
Schedule of Available-for-sale Securities
Continuous unrealized loss investments, number of positions		2
Less Than 12 Months, Fair value		0
Less Than 12 Months, Unrealized losses		0
12 Months or More, Fair value		60
12 Months or More, Unrealized losses		1
Total, Fair value		60
Total, Unrealized losses		$ 1