Income Taxes (Income Tax Provision Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Plant Office Closures			$ 52	$ 0	$ 0
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities			6	55	33
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions					29
Asset impairments			0	(2)	(126)
Singapore contract termination			0	$ 0	$ (174)
Tax Credit Carryforward, Amount			240
Tax Credit Carryforward, Valuation Allowance			164
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense (Benefit)			370
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense (Benefit) Net			197
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability, Provisional Income Tax (Expense) Benefit			107
Accumulated but undistributed earnings permanently reinvested in business			$ 3,000
Effective income tax rate			20.00%	12.00%	41.00%
SINGAPORE
Tax Credit Carryforward [Line Items]
Singapore contract termination					$ (174)
Nanjing, China [Member]
Tax Credit Carryforward [Line Items]
Asset impairments					$ (123)
Acetyl Intermediates [Member]
Tax Credit Carryforward [Line Items]
Plant Office Closures			$ 51
Acetyl Intermediates [Member] | SINGAPORE
Tax Credit Carryforward [Line Items]
Singapore contract termination	$ (174)
Acetyl Intermediates [Member] | Nanjing, China [Member]
Tax Credit Carryforward [Line Items]
Asset impairments		$ (123)