Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income, before tax amount	$ 4,904	$ 6,460
Income tax expense	1,712	2,255
Net income	3,192	4,205
Investment securities available for sale:
Unrealized holding gains on securities arising during the period, before tax	(144)	152
Unrealized holding gains on securities arising during the period, tax	(58)	55
Unrealized holding gains on securities arising during the period, net	(86)	97
Less: reclassification adjustment for gains on securities included in net income, before tax	0	94
Less: reclassification adjustment for gains on securities included in net income, tax	0	33
Total reclassification adjustment for gains on securities included in net income	0	61
Total unrealized gains on securities available for sale, before tax	(144)	58
Total unrealized gains on securities available for sale, tax	(58)	22
Total unrealized gains on securities available for sale, net of tax	(86)	36
Adjustments related to defined benefit plan:
Amortization of prior service cost, before tax	21	20
Amortization of prior service cost, tax	9	0
Amortization of prior service cost, net of tax	12	20
Total adjustments related to defined benefit plan, before tax	21	20
Total adjustments related to defined benefit plan, tax	9	0
Total adjustments related to defined benefit plan	12	20
Net unrealized (losses) from cash flow hedges:
Unrealized holding loss on cash flow hedges arising during the period, before tax	81	(492)
Unrealized holding loss on cash flow hedges arising during the period, tax	33	(202)
Unrealized holding loss on cash flow hedges arising during the period, net of tax	48	(290)
Total unrealized loss on cash flow hedges, before tax	81	(492)
Total unrealized loss on cash flow hedges, tax	33	(202)
Total unrealized loss on cash flow hedges, net of tax	48	(290)
Total other comprehensive income, before tax	(42)	(414)
Total other comprehensive income, tax	(16)	(180)
Total other comprehensive income, net	(26)	(234)
Total comprehensive income, before tax	4,862	6,046
Total comprehensive income, tax	1,696	2,075
Total comprehensive income	$ 3,166	$ 3,971