Pension and Postretirement Plans (Asset Allocation) (Details 2) - Defined Benefit Pension Plans [Member]	Mar. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	100.00%	100.00%
U.S. [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	49.00%	53.00%
U.S. [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	30.00%	30.00%
U.S. [Member] | Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	12.00%	11.00%
International [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Assets Allocation (Percent)	9.00%	6.00%