Postretirement Benefit Plans (Net Funded Status) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Postretirement Health And Life Coverage [Member]
Change in benefit obligations:
Benefit obligations		$ 342	$ 404
Change in benefit obligations: Service cost		2	3	$ 3
Change in benefit obligations: Interest cost		9	13	17
Change in benefit obligations: Change in experience		73	45
Change in benefit obligations: Change in assumptions		(5)	27
Change in benefit obligations/fair value of plan assets: Benefit payments		(22)	(150)
Benefit obligations	$ 399	399	342	404
Change in fair value of plan assets:
Change in fair value of plan assets: Employer contributions		22	150
Change in benefit obligations/fair value of plan assets: Benefit payments		(22)	(150)
Funded status at year end	(399)	(399)	(342)
Director's Retirement Plan [Member]
Change in benefit obligations:
Benefit obligations		1,142	1,077
Change in benefit obligations: Service cost		47	49	51
Change in benefit obligations: Interest cost		26	31	42
Change in benefit obligations: Actuarial loss (gain)		61	7
Change in benefit obligations: Change in assumptions		25	65
Change in benefit obligations/fair value of plan assets: Benefit payments		(106)	(87)
Benefit obligations	1,195	1,195	1,142	1,077
Change in fair value of plan assets:
Change in fair value of plan assets: Employer contributions		106	87
Change in benefit obligations/fair value of plan assets: Benefit payments		(106)	(87)
Funded status at year end	(1,195)	(1,195)	(1,142)
Scottdale Defined Benefit Pension Plan [Member]
Change in benefit obligations:
Benefit obligations		5,401	5,587
Change in benefit obligations: Service cost		83	79
Change in benefit obligations: Interest cost		134	180
Change in benefit obligations: Settlement (gain) loss			(85)
Change in benefit obligations: Actuarial loss (gain)		(309)	495
Change in benefit obligations/fair value of plan assets: Settlement payments		(378)	(769)
Change in benefit obligations/fair value of plan assets: Benefit payments		(87)	(86)
Benefit obligations	4,844	4,844	5,401	5,587
Change in fair value of plan assets:
Fair value of plan assets		4,939	5,404
Change in fair value of plan assets: Return on plan assets		582	229
Change in fair value of plan assets: Employer contributions		285	200
Change in benefit obligations/fair value of plan assets: Benefit payments		(87)	(86)
Change in fair value of plan assets: Administrative expenses		(39)	(39)
Change in benefit obligations/fair value of plan assets: Settlement payments		(378)	(769)
Fair value of plan assets	5,302	5,302	4,939	$ 5,404
Funded status at year end	458	458	$ (462)
Riverview Defined Benefit Plan [Member]
Change in benefit obligations:
Benefit obligations	8,278
Change in benefit obligations: Interest cost	19
Change in benefit obligations: Actuarial loss (gain)	(86)
Change in benefit obligations/fair value of plan assets: Benefit payments	(46)
Benefit obligations	8,165	8,165
Change in fair value of plan assets:
Fair value of plan assets	8,894
Change in fair value of plan assets: Return on plan assets	136
Change in benefit obligations/fair value of plan assets: Benefit payments	(46)
Fair value of plan assets	8,984	8,984
Funded status at year end	$ 819	$ 819