Pensions and Postretirement Benefits (Summary of Pension Plan Weighted-Average Asset Allocation) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Summary of pension plan weighted-average asset allocation/summary of reconciliation of level 3 assets
Target allocation	100.00%
Weighted-average asset allocations	100.00%	100.00%
Equity securities
Summary of pension plan weighted-average asset allocation/summary of reconciliation of level 3 assets
Target allocation, minimum	45.00%
Target allocation, maximum	75.00%
Weighted-average asset allocations	61.90%	62.70%
Debt securities
Summary of pension plan weighted-average asset allocation/summary of reconciliation of level 3 assets
Target allocation, minimum	20.00%
Target allocation, maximum	40.00%
Weighted-average asset allocations	24.60%	25.40%
Other
Summary of pension plan weighted-average asset allocation/summary of reconciliation of level 3 assets
Target allocation, minimum	0.00%
Target allocation, maximum	20.00%
Weighted-average asset allocations	13.50%	11.90%