Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Environmental contingency accrual		$ 49	$ 49
Minimum [Member]
Loss Contingencies [Line Items]
Reasonably possible additional loss - Environmental		55
Maximum [Member]
Loss Contingencies [Line Items]
Reasonably possible additional loss - Environmental		110
PolyOne [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 17
Gain Contingency, Unrecorded Amount	$ 6
Environmental Protection Agency [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Environmental Remediation Expense Estimated		200
Environmental Protection Agency [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Environmental Remediation Expense Estimated		250
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost		1
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost		$ 3