Accumulated Other Comprehensive Income (Loss) Change in other comprehensive income (loss) for the period (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period	$ 232	$ 6,467	$ 3,926
Unrealized holding gains (net of tax, $1,511, $3,212, and 1,979 for 2012, 2013 and 2014, respectively)	3,841	(6,234)	2,932
Reclassification adjustment (net of tax, $151, $142, and $63 for 2012, 2013 and 2014, respectively)	(123)
Unrealized gain on interest rate swaps (net of tax, $50, $142, and $82 for 2012, 2013 and 2014, respectively)	(160)
Reclassification adjustment for loss on interest rate swap ineffectiveness included in net income, net of tax of ($2) for 2014	4	0	0
Balance end of period	3,794	232	6,467
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Unrealized holding gains losses arising during the period, taxes	1,979	(3,212)	1,511
Reclassification adjustment for investment securities, taxes	63	142	151
Unrealized gain on interest rate swaps, tax	(82)	142	(50)
Reclassification adjustment for loss on interest rate swap ineffectiveness, tax	2	0	0
Unrealized Gains (Losses) on Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period	261	6,771	4,133
Unrealized holding gains (net of tax, $1,511, $3,212, and 1,979 for 2012, 2013 and 2014, respectively)	3,841	(6,234)	2,932
Reclassification adjustment (net of tax, $151, $142, and $63 for 2012, 2013 and 2014, respectively)	(123)	(276)	(294)
Unrealized gain on interest rate swaps (net of tax, $50, $142, and $82 for 2012, 2013 and 2014, respectively)	0	0	0
Reclassification adjustment for loss on interest rate swap ineffectiveness included in net income, net of tax of ($2) for 2014	0
Balance end of period	3,979	261	6,771
Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning of period	(29)	(304)	(207)
Unrealized holding gains (net of tax, $1,511, $3,212, and 1,979 for 2012, 2013 and 2014, respectively)	0	0	0
Reclassification adjustment (net of tax, $151, $142, and $63 for 2012, 2013 and 2014, respectively)	0	0	0
Unrealized gain on interest rate swaps (net of tax, $50, $142, and $82 for 2012, 2013 and 2014, respectively)	(160)	275	(97)
Reclassification adjustment for loss on interest rate swap ineffectiveness included in net income, net of tax of ($2) for 2014	4
Balance end of period	(185)	(29)	(304)
Defined Benefit Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification adjustment (net of tax, $151, $142, and $63 for 2012, 2013 and 2014, respectively)		(276)	(294)
Unrealized gain on interest rate swaps (net of tax, $50, $142, and $82 for 2012, 2013 and 2014, respectively)		275	(97)
Balance end of period		$ 232