Schedule of Changes In Each Component of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Nine months ended September 30,
Beginning Balance	$ 636,908	$ 503,753	$ 600,764	$ 502,507
Other comprehensive income	6,307	(4,325)	25,877	(14,976)
Adoption of new accounting pronouncement				0
Ending balance	649,603	512,026	649,603	512,026
Defined Benefit Pension Plans
Nine months ended September 30,
Beginning Balance	(5,871)	(5,033)	(5,871)	(5,033)
Ending balance	(5,871)	(5,033)	(5,871)	(5,033)
Unrealized Gain (Losses) on Securities Available-for-Sale
Nine months ended September 30,
Beginning Balance	10,959	(13,919)	(8,611)	(611)
Other comprehensive loss before reclassifications	6,277	(4,325)	25,931	(14,976)
Amounts reclassified from other comprehensive loss	30	0	(54)	0
Other comprehensive income	6,307	(4,325)	25,877	(14,976)
Adoption of new accounting pronouncement		0		2,657
Ending balance	17,266	(18,244)	17,266	(18,244)
Accumulated Other Comprehensive Income (Loss)
Nine months ended September 30,
Beginning Balance	5,088	(18,952)	(14,482)	(5,644)
Other comprehensive loss before reclassifications	6,277	(4,325)	25,931	(14,976)
Amounts reclassified from other comprehensive loss	30	0	(54)	0
Other comprehensive income	6,307	(4,325)	25,877	(14,976)
Adoption of new accounting pronouncement				2,657
Ending balance	$ 11,395	$ (23,277)	$ 11,395	$ (23,277)