Commitments and Contingencies (Details) - Environmental Liabilities - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Accrued Environmental Loss Contingencies, Current		$ 18
Liability	$ 49	51
Estimated Litigation Liability, Current	1	1
Estimated Litigation Liability	1	1
Geismar, LA
Accrual for Environmental Loss Contingencies	$ 12	12
Discount rate assumed to record at present value	3.00%
Undiscounted Liability Expected to be Paid	next 20 years
Accrual for Environmental Loss Contingencies, Gross	$ 16
Accrual for Environmental Loss Contingencies, Undiscounted, Due Ratably over the Next Five Years	6
Less than 1%
Accrual for Environmental Loss Contingencies	3	3
Equal to or greater than 1%
Accrual for Environmental Loss Contingencies	6	6
Currently-owned
Accrual for Environmental Loss Contingencies	9	8
Remediation
Accrual for Environmental Loss Contingencies	19	21
Accrued Environmental Loss Contingencies, Current	10
Estimated Litigation Liability, Noncurrent	9
Monitoring only
Accrual for Environmental Loss Contingencies	0	$ 1
Maximum [Member]
Site Contingency, Loss Exposure Not Accrued, Best Estimate	94
Maximum [Member] | Geismar, LA
Liability	22
Maximum [Member] | Less than 1%
Liability	6
Maximum [Member] | Equal to or greater than 1%
Liability	14
Maximum [Member] | Currently-owned
Liability	14
Maximum [Member] | Remediation
Liability	37
Maximum [Member] | Monitoring only
Liability	1
Minimum [Member]
Site Contingency, Loss Exposure Not Accrued, Best Estimate	36
Minimum [Member] | Geismar, LA
Liability	9
Minimum [Member] | Less than 1%
Liability	2
Minimum [Member] | Equal to or greater than 1%
Liability	5
Minimum [Member] | Currently-owned
Liability	4
Minimum [Member] | Remediation
Liability	16
Minimum [Member] | Monitoring only
Liability	$ 0