Securities Amortized costs and fair values of securities available for sale (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 329,159	$ 328,027
Gross Unrealized Gains	8,083	5,815
Gross Unrealized Losses	(2,208)	(5,419)
Fair Value	335,034	328,423
U.S. government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,330	21,367
Gross Unrealized Gains	243	304
Gross Unrealized Losses	(210)	(332)
Fair Value	32,363	21,339
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	58,141	68,904
Gross Unrealized Gains	2,351	1,083
Gross Unrealized Losses	(482)	(2,749)
Fair Value	60,010	67,238
Mortgage-backed securities, Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	164,872	166,095
Gross Unrealized Gains	4,691	3,539
Gross Unrealized Losses	(800)	(1,624)
Fair Value	168,763	168,010
Mortgage-backed securities, Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,978	22,029
Gross Unrealized Gains	124	116
Gross Unrealized Losses	(151)	(211)
Fair Value	27,951	21,934
Other asset backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,215	33,883
Gross Unrealized Gains	523	710
Gross Unrealized Losses	(48)	(175)
Fair Value	27,690	34,418
Corporate preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15	69
Gross Unrealized Gains	0	5
Gross Unrealized Losses	0	0
Fair Value	15	74
Corporate securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,608	15,680
Gross Unrealized Gains	151	58
Gross Unrealized Losses	(517)	(328)
Fair Value	$ 18,242	$ 15,410