Commitments and Contingencies (Additional Information) (Detail) - USD ($) $ in Millions		1 Months Ended	9 Months Ended
	Jun. 18, 2018	May 31, 2017	Sep. 30, 2018	Dec. 31, 2017
Environmental Loss Contingencies [Line Items]
Environmental Loss contingency accrual			$ 57	$ 49
Site Contingency, Percentage of Cost Potentially of Other Responsible Parties [Line Items]			100.00%
PolyOne [Member] | Pending Litigation [Member]
Environmental Loss Contingencies [Line Items]
Maximum Expected Damages		$ 17
Minimum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss			$ 55
Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss			110
Environmental Protection Agency [Member] | Minimum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Remediation Expense			200
Environmental Protection Agency [Member] | Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Remediation Expense			250
Environmental Protection Agency [Member] | Operation and Maintenance [Member]
Environmental Loss Contingencies [Line Items]
Environmental Remediation Expense	$ 107
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Minimum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost			1
Environmental Protection Agency [Member] | Operation and Maintenance [Member] | Maximum [Member]
Environmental Loss Contingencies [Line Items]
Environmental Exit Costs, Anticipated Cost			3
Affiliated Entity [Member] | LACC [Member]
Environmental Loss Contingencies [Line Items]
Maximum Capital Commitment			$ 225
Ownership interest (in percent)			10.00%
Funding to related parties			$ 178