Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 13,694	$ 13,261
Operating Segments [Member] | Olefins [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,906	1,991
Operating Segments [Member] | Vinyls
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	10,419	10,597
Corporate and other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 1,369	$ 673