Employee Benefit Plans (Schedule of Benefits Plans) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Pension Benefit Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost		$ 591	$ 674
Interest Cost		761	677
Expected Return on Assets		(1,760)	(1,556)
Amortization of Unrecognized Losses		418	717
Net Periodic Benefit Cost (Benefit)	[1]	10	512
Other Benefits Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost		200	229
Interest Cost		331	309
Expected Return on Assets		(887)	(786)
Amortization of Unrecognized Losses			132
Net Periodic Benefit Cost (Benefit)	[1]	$ (356)	$ (116)

[1] Service cost is included in Operations and Maintenance expense on the Condensed Consolidated Statements of Income; all other amounts are included in Other Income/Expense, net.