Accumulated Other Comprehensive Loss (Schedule of Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax		$ (3,119)
Tax		(527)
After-Tax		(2,592)
Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax	$ (983)
After-Tax	(983)
Accumulated Defined Benefit Plans Adjustment, Actuarial Gain (Loss) Attributable to Parent [Member] \| Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax	(1,544)	(1,025)
After-Tax	(1,544)	(1,025)
Accumulated Defined Benefit Plans Adjustment, Termination Gain (Loss) Attributable to Parent [Member] \| Postretirement Benefit Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax		4,369
After-Tax		4,369
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Accumulated Defined Benefit Plans Adjustment, Termination Gain (Loss) Attributable to Parent [Member] \| Postretirement Benefit Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax		(6,637)
Tax		(527)
After-Tax		(6,110)
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] \| Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax	561	549
After-Tax	$ 561	549
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] \| Postretirement Benefit Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax		(389)
After-Tax		(389)
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] \| Postretirement Benefit Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Pre-Tax		14
After-Tax		$ 14

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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