Securities Amortized costs and fair values of securities available for sale (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 347,075	$ 342,233
Gross Unrealized Gains	7,264	8,068
Gross Unrealized Losses	(2,349)	(2,038)
Fair Value	351,990	348,263
U.S. government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	45,291	41,317
Gross Unrealized Gains	336	283
Gross Unrealized Losses	(156)	(203)
Fair Value	45,471	41,397
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	50
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	71,900	55,541
Gross Unrealized Gains	1,864	2,408
Gross Unrealized Losses	(521)	(209)
Fair Value	73,243	57,740
Mortgage-backed securities, Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	142,586	169,257
Gross Unrealized Gains	4,323	4,698
Gross Unrealized Losses	(543)	(742)
Fair Value	146,366	173,213
Mortgage-backed securities, Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,892	28,235
Gross Unrealized Gains	28	115
Gross Unrealized Losses	(54)	(227)
Fair Value	17,866	28,123
Other asset backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	51,803	31,338
Gross Unrealized Gains	698	433
Gross Unrealized Losses	(308)	(58)
Fair Value	52,193	31,713
Corporate securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,553	16,545
Gross Unrealized Gains	15	131
Gross Unrealized Losses	(767)	(599)
Fair Value	$ 16,801	$ 16,077