Postretirement Benefit Plans (Net Periodic Benefit (Income) Costs) (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]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 2	$ 3	$ 3
Interest cost		9	13	17
Amortization of prior service cost		(25)	(25)	(25)
Amortization of net (gain) or loss		9		(5)
Net periodic postretirement benefit (income) cost		(5)	(9)	(10)
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		47	49	51
Interest cost		26	31	42
Amortization of prior service cost		7
Net periodic postretirement benefit (income) cost		80	80	$ 93
Scottdale Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		83	79
Interest cost		134	180
Expected return on plan assets		(227)	(273)
Net periodic postretirement benefit (income) cost		$ (10)	$ (14)
Riverview Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 19
Expected return on plan assets	(46)
Net periodic postretirement benefit (income) cost	$ (27)