Pension and Postretirement Plans (Asset Allocation) (Details 2) - Defined Benefit Pension Plans [Member]	Mar. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	100.00%	100.00%
U.S. equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	61.00%	58.00%
Private investment fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	17.00%	18.00%
U.S. stock index fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	9.00%	9.00%
International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	8.00%	8.00%
U.S. fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	5.00%	7.00%