Segment Information (Total Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 14,163	$ 13,261
Operating Segments [Member] | Olefins [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,978	1,991
Operating Segments [Member] | Vinyls [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	10,434	10,597
Corporate and other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 1,751	$ 673