Accumulated Other Comprehensive Income (Loss), Accumulated Other Comprehensive Income (Loss) Income Balances, Net of Tax (Details) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance	[1]	$ 578,593	$ 571,031	$ 568,161	$ 553,421	$ 548,185	$ 538,257	$ 568,161	$ 538,257
Other comprehensive income (loss) - before reclassifications		(566)			(198)			(4,405)	8,432
Amount reclassified from accumulated other comprehensive income		30			(201)			(227)	(1,356)
Other comprehensive (loss) income, net of tax		(536)	572	(4,668)	(399)	544	6,931	(4,632)	7,076
Balance	[1]	586,683	578,593	571,031	560,528	553,421	548,185	586,683	560,528
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance	[1]	7,840	7,268	11,936	11,936	11,392	4,461	11,936	4,461
Other comprehensive (loss) income, net of tax		(536)	572	(4,668)	(399)	544	6,931
Balance	[1]	7,304	7,840	7,268	11,537	11,936	11,392	7,304	11,537
Net Unrealized Holding (Gain) Loss on Securities Available for Sale, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		3,347		7,186	8,061		286	7,186	286
Other comprehensive income (loss) - before reclassifications		(566)			(198)			(4,405)	8,432
Amount reclassified from accumulated other comprehensive income		0			0			0	(855)
Other comprehensive (loss) income, net of tax		(566)			(198)			(4,405)	7,577
Balance		2,781	3,347		7,863	8,061		2,781	7,863
Net Change in Overfunded Position in Pension and Postretirement Plans Arising During the Year, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		6,084		6,084	4,840		4,840	6,084	4,840
Other comprehensive income (loss) - before reclassifications		0			0			0	0
Amount reclassified from accumulated other comprehensive income		0			0			0	0
Other comprehensive (loss) income, net of tax		0			0			0	0
Balance		6,084	6,084		4,840	4,840		6,084	4,840
Net Change in Net Actuarial (Gain) Loss and Prior Service Credit on Pension and Postretirement Benefit Plans, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		(1,591)		$ (1,334)	(965)		$ (665)	(1,334)	(665)
Other comprehensive income (loss) - before reclassifications		0			0			0	0
Amount reclassified from accumulated other comprehensive income		30			(201)			(227)	(501)
Other comprehensive (loss) income, net of tax		30			(201)			(227)	(501)
Balance		$ (1,561)	$ (1,591)		$ (1,166)	$ (965)		$ (1,561)	$ (1,166)

[1] All periods presented have been adjusted for the 1 for 5 reverse stock split which occurred on May 28, 2021.