Other (Charges) Gains, Net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Other plant/office closures	$ (13)	$ 0	$ (13)	$ 50
Employee termination benefits	$ (1)	0	$ (4)	$ (3)
Acetyl Intermediates [Member]
Restructuring Cost and Reserve [Line Items]
Other plant/office closures		50
Acetyl Intermediates [Member] | Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Other plant/office closures		24
Acetyl Intermediates [Member] | Non-income tax receivable adjustment [Member]
Restructuring Cost and Reserve [Line Items]
Other plant/office closures		$ 18