Revenues, Geographic location (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of revenue [Abstract]
Sales and other operating revenues	$ 6,776	$ 8,722	$ 19,816	$ 26,548
United States [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	2,983	4,190	8,587	12,333
Germany [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	494	671	1,533	2,112
China [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	369	299	914	895
Italy [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	290	361	884	1,133
Mexico [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	285	390	868	1,349
France [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	213	324	644	1,049
Japan [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	161	282	639	740
Poland [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	205	238	617	759
The Netherlands [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	197	226	562	748
Other [Member]
Disaggregation of revenue [Abstract]
Sales and other operating revenues	$ 1,579	$ 1,741	$ 4,568	$ 5,430