Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning	$ 239,246	$ 233,478	$ 240,825	$ 228,048
Before reclassifications	960	712	(2,480)	3,370
Reclassifications	0	0	0	(175)
Balance ending	239,952	237,047	239,952	237,047
Total [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning	603		4,043
Balance ending	1,563	3,868	1,563	3,868
Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Before reclassifications	958	711	(2,483)	3,369
Reclassifications	0	0	0	(175)
Balance ending	1,866		1,866
Changes in Pension Plan Assets and Benefit Obligations [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Before reclassifications	2	1	3	1
Reclassifications	0	0	0	0
Balance ending	(303)		(303)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Total [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning	603	3,156	4,043	673
Balance ending		3,868		3,868
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning	908	3,340	4,349	857
Balance ending		4,051		4,051
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Changes in Pension Plan Assets and Benefit Obligations [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance beginning	$ (305)	(184)	$ (306)	(184)
Balance ending		$ (183)		$ (183)