Other (Charges) Gains, Net (Schedule of Other (Charges) Gains, Net) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring		$ (1)	$ (9)	$ (5)	$ (17)
Asset impairments		0	(2)	(2)	(31)
Plant/office closures		1	1	10	6
Commercial disputes		0	0	0	6
European Commission investigation		0	0	0	(2)
Other		0	0	0	1
Total		0	(10)	3	(37)
Restructuring Reserve [Roll Forward]
Additions		1	$ 9	5	17
Employee Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring				(5)
Restructuring Reserve [Roll Forward]
Beginning balance				11
Additions				5
Cash payments				(7)
Exchange rate changes				(1)
Ending balance		8		8
Employee Termination Benefits | Engineered Materials
Restructuring Cost and Reserve [Line Items]
Restructuring				(3)
Restructuring Reserve [Roll Forward]
Beginning balance				8
Additions				3
Cash payments				(4)
Exchange rate changes				(1)
Ending balance		6		6
Employee Termination Benefits | Acetate Tow
Restructuring Cost and Reserve [Line Items]
Restructuring				0
Restructuring Reserve [Roll Forward]
Beginning balance				1
Additions				0
Cash payments				0
Exchange rate changes				0
Ending balance		1		1
Employee Termination Benefits | Acetyl Chain
Restructuring Cost and Reserve [Line Items]
Restructuring				0
Restructuring Reserve [Roll Forward]
Beginning balance				0
Additions				0
Cash payments				0
Exchange rate changes				0
Ending balance		0		0
Employee Termination Benefits | Other
Restructuring Cost and Reserve [Line Items]
Restructuring				(2)
Restructuring Reserve [Roll Forward]
Beginning balance				2
Additions				2
Cash payments				(3)
Exchange rate changes				0
Ending balance		$ 1		1
Lebanon, Tennessee [Member] | Engineered Materials
Restructuring Cost and Reserve [Line Items]
Asset impairments					(4)
Europe [Member] | Engineered Materials
Restructuring Cost and Reserve [Line Items]
Asset impairments					$ (26)
Plant/office closures	[1]			$ 9

[1] Included in Other (charges) gains, net in the unaudited interim consolidated statement of operations (Note 12).