CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 25,257	$ 23,881	$ 14,816
Unrealized gains/(losses) on available for sale securities
Unrealized holding gains/(losses) arising during period	2,500	(242)	128
Less: reclassification adjustment for losses/(gains) included in net income	62	(2)	1
Total unrealized gains/(losses) on securities	2,562	(244)	129
Derivatives
Change in interest rate contracts	821	751
Defined benefit retirement plans
Change in retirement liabilities	623	89	3,871
Other comprehensive income/(loss)	4,006	596	4,000
Comprehensive income	$ 29,263	$ 24,477	$ 18,816

Other comprehensive income (loss) derivatives net of tax period increase decrease.

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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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Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities and unrealized holding gain (loss) related to transfers of securities into the available-for-sale classification and out of the held-to-maturity classification.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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