Postretirement Benefit Plans (Amounts Recognized in Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Postretirement Health And Life Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain), pretax	$ 82	$ 22
Net prior service cost, pretax	(15)	(40)
Director's Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain), pretax	189	110
Scottdale Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain), pretax	(602)	$ (24)
Riverview Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain), pretax	$ (176)