Environmental (Schedule of Environmental Ownership and Liability Percentages) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Environmental Disclosure [Line Items]
Reserves		$ 73	$ 64
InfraServ GmbH & Co. Gendorf KG [Member]
Environmental Disclosure [Line Items]
Ownership percentage		39.00%
Liability percentage		10.00%
Reserves	[1]	$ 9
InfraServ Gmbh & Co. Hoechst KG [Member]
Environmental Disclosure [Line Items]
Ownership percentage		32.00%
Liability percentage		40.00%
Reserves	[1]	$ 71
InfraServ GmbH & Co. Knapsack KG [Member]
Environmental Disclosure [Line Items]
Ownership percentage		27.00%
Liability percentage		22.00%
Reserves	[1]	$ 1

[1] Gross reserves maintained by the respective InfraServ entity.