Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income, before tax amount	$ 6,745	$ 5,771	$ 19,958	$ 16,025
Income tax expense	1,255	2,014	3,841	5,632
Net income	5,490	3,757	16,117	10,393
Investment securities available for sale:
Unrealized holding (losses) gains on securities arising during the period, before tax	(293)	(128)	(1,236)	137
Unrealized holding (losses) gains on securities arising during the period, tax	(82)	(55)	(371)	50
Unrealized holding (losses) gains on securities arising during the period, net	(211)	(73)	(865)	87
Less: reclassification adjustment for gains on securities included in net income, before tax	2	53	9	69
Less: reclassification adjustment for gains on securities included in net income, tax	0	19	1	24
Less: reclassification adjustment for gains on securities included in net income, net	2	34	8	45
Total unrealized (losses) gains on securities available for sale, before tax	(295)	(181)	(1,245)	68
Total unrealized (losses) gains on securities available for sale, tax	(82)	(74)	(372)	26
Total unrealized (losses) gains on securities available for sale, net of tax	(213)	(107)	(873)	42
Adjustments related to defined benefit plan:
Amortization of prior service cost, before tax	21	21	63	63
Amortization of prior service cost, tax	6	9	167	26
Amortization of prior service cost, net of tax	15	12	(104)	37
Total adjustments related to defined benefit plan, before tax	21	21	63	63
Total adjustments related to defined benefit plan, tax	6	9	167	26
Total adjustments related to defined benefit plan, net	15	12	(104)	37
Net unrealized (losses) gains from cash flow hedges:
Unrealized holding (losses) gains on cash flow hedges arising during the period, before tax	(7)	48	658	(183)
Unrealized holding (losses) gains on cash flow hedges arising during the period, tax	(2)	20	55	(75)
Unrealized holding (losses) gains on cash flow hedges arising during the period, net of tax	(5)	28	603	(108)
Total unrealized (losses) gains on cash flow hedges, before tax	(7)	48	658	(183)
Total unrealized (losses) gains on cash flow hedges, tax	(2)	20	55	(75)
Total unrealized (losses) gains on cash flow hedges, net of tax	(5)	28	603	(108)
Total other comprehensive income (loss), before tax	(281)	(112)	(524)	(52)
Total other comprehensive income (loss), tax	(78)	(45)	(150)	(23)
Total other comprehensive income (loss), net	(203)	(67)	(374)	(29)
Total comprehensive income, before tax	6,464	5,659	19,434	15,973
Total comprehensive income, tax	1,177	1,969	3,691	5,609
Total comprehensive income	$ 5,287	$ 3,690	$ 15,743	$ 10,364