Employee Benefits Assumptions (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	4.58%	4.58%
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	5.02%	5.88%
Pension Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.64%	3.43%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.65%	3.65%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.43%	4.25%
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	7.00%	7.00%
Other Pension, Postretirement and Supplemental Plans [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.64%	3.43%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	4.10%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.43%	3.43%
Maximum [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.92%	3.47%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.47%	4.26%
Minimum [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.22%	3.19%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.19%	3.11%