UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 6,111	$ 4,514	$ 11,916	$ 8,842
Unrealized (losses)/gains on available for sale securities
Unrealized holding (losses)/gains arising during period	(423)	493	(1,775)	682
Less: reclassification adjustment for (gains)/losses included in net income	(2)		(2)	1
Total unrealized (losses)/gains on securities	(425)	493	(1,777)	683
Defined benefit retirement plans
Change in retirement liabilities	10	133	20	265
Other comprehensive (loss)/income	(415)	626	(1,757)	948
Comprehensive income	$ 5,696	$ 5,140	$ 10,159	$ 9,790

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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