Employee Benefit Plans (Schedule of Benefits Plans) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefit Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost		$ 591	$ 674	$ 1,181	$ 1,348
Interest Cost		761	677	1,521	1,353
Expected Return on Assets		(1,760)	(1,556)	(3,520)	(3,114)
Amortization of Unrecognized Losses		418	717	837	1,434
Net Periodic Benefit Cost (Benefit)	[1]	10	512	19	1,021
Other Benefits Plan [Member]
Periodic costs for employee retirement benefit plans
Service Cost		200	229	399	458
Interest Cost		331	309	663	618
Expected Return on Assets		(887)	(786)	(1,773)	(1,571)
Amortization of Unrecognized Losses			132		264
Net Periodic Benefit Cost (Benefit)	[1]	$ (356)	$ (116)	$ (711)	$ (231)

[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.