Revenues, Key product revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of revenue [Abstract]
Sales and other operating revenues	$ 7,494	$ 8,778
Olefins & co-products [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	667	748
Polyethylene [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	1,459	1,666
Polypropylene [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	1,101	1,315
Propylene oxide and derivatives [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	464	528
Oxyfuels and related products [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	707	664
Intermediate chemicals [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	544	640
Compounding and solutions [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	912	1,140
Advanced polymers [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	181	198
Refined products [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	1,336	1,743
Other [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	$ 123	$ 136