Environmental (Schedule of Environmental Remediation Reserves) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Environmental Remediation Obligations [Abstract]
Demerger obligations (Note 19)	$ 25	$ 26
Divestiture obligations (Note 19)	14	16
Active sites	13	14
US Superfund sites	11	11
Other environmental remediation liabilities	2	2
Total	$ 65	$ 69

Total costs accrued as of the balance sheet date for environmental loss contingencies.

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