Revenue Recognition - Disaggregation of revenue (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation of revenue
Revenue from customers	$ 4,257	$ 11,813
United States
Disaggregation of revenue
Revenue from customers	2,703	7,815
Middle East
Disaggregation of revenue
Revenue from customers	1,281	3,226
Latin America
Disaggregation of revenue
Revenue from customers	252	713
Other International
Disaggregation of revenue
Revenue from customers	21	59
Intersegment Eliminations
Disaggregation of revenue
Revenue from customers	(225)	(686)
Intersegment Eliminations | United States
Disaggregation of revenue
Revenue from customers	(225)	(686)
Intersegment Eliminations | Middle East
Disaggregation of revenue
Revenue from customers	0	0
Intersegment Eliminations | Latin America
Disaggregation of revenue
Revenue from customers	0	0
Intersegment Eliminations | Other International
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment
Disaggregation of revenue
Revenue from customers	2,889	7,874
Oil and Gas Segment | Oil
Disaggregation of revenue
Revenue from customers	2,539	6,961
Oil and Gas Segment | NGL
Disaggregation of revenue
Revenue from customers	216	531
Oil and Gas Segment | Gas
Disaggregation of revenue
Revenue from customers	132	371
Oil and Gas Segment | Other
Disaggregation of revenue
Revenue from customers	2	11
Oil and Gas Segment | United States
Disaggregation of revenue
Revenue from customers	1,515	4,397
Oil and Gas Segment | United States | Oil
Disaggregation of revenue
Revenue from customers	1,326	3,907
Oil and Gas Segment | United States | NGL
Disaggregation of revenue
Revenue from customers	139	339
Oil and Gas Segment | United States | Gas
Disaggregation of revenue
Revenue from customers	47	141
Oil and Gas Segment | United States | Other
Disaggregation of revenue
Revenue from customers	3	10
Oil and Gas Segment | Middle East
Disaggregation of revenue
Revenue from customers	1,173	2,918
Oil and Gas Segment | Middle East | Oil
Disaggregation of revenue
Revenue from customers	1,016	2,507
Oil and Gas Segment | Middle East | NGL
Disaggregation of revenue
Revenue from customers	77	192
Oil and Gas Segment | Middle East | Gas
Disaggregation of revenue
Revenue from customers	80	218
Oil and Gas Segment | Middle East | Other
Disaggregation of revenue
Revenue from customers	0	1
Oil and Gas Segment | Latin America
Disaggregation of revenue
Revenue from customers	201	559
Oil and Gas Segment | Latin America | Oil
Disaggregation of revenue
Revenue from customers	197	547
Oil and Gas Segment | Latin America | NGL
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Latin America | Gas
Disaggregation of revenue
Revenue from customers	5	12
Oil and Gas Segment | Latin America | Other
Disaggregation of revenue
Revenue from customers	(1)	0
Oil and Gas Segment | Other International
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | Oil
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | NGL
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | Gas
Disaggregation of revenue
Revenue from customers	0	0
Oil and Gas Segment | Other International | Other
Disaggregation of revenue
Revenue from customers	0	0
Chemical Segment
Disaggregation of revenue
Revenue from customers	1,184	3,507
Chemical Segment | United States
Disaggregation of revenue
Revenue from customers	1,112	3,294
Chemical Segment | Middle East
Disaggregation of revenue
Revenue from customers	0	0
Chemical Segment | Latin America
Disaggregation of revenue
Revenue from customers	51	154
Chemical Segment | Other International
Disaggregation of revenue
Revenue from customers	21	59
Midstream Segment
Disaggregation of revenue
Revenue from customers	409	1,118
Midstream Segment | Marketing and Trading
Disaggregation of revenue
Revenue from customers	3	11
Midstream Segment | Gas Processing
Disaggregation of revenue
Revenue from customers	256	724
Midstream Segment | Pipelines
Disaggregation of revenue
Revenue from customers	115	310
Midstream Segment | Power and Other
Disaggregation of revenue
Revenue from customers	35	73
Midstream Segment | United States
Disaggregation of revenue
Revenue from customers	301	810
Midstream Segment | United States | Marketing and Trading
Disaggregation of revenue
Revenue from customers	3	11
Midstream Segment | United States | Gas Processing
Disaggregation of revenue
Revenue from customers	148	416
Midstream Segment | United States | Pipelines
Disaggregation of revenue
Revenue from customers	115	310
Midstream Segment | United States | Power and Other
Disaggregation of revenue
Revenue from customers	35	73
Midstream Segment | Middle East
Disaggregation of revenue
Revenue from customers	108	308
Midstream Segment | Middle East | Marketing and Trading
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Middle East | Gas Processing
Disaggregation of revenue
Revenue from customers	108	308
Midstream Segment | Middle East | Pipelines
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Middle East | Power and Other
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Marketing and Trading
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Pipelines
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Latin America | Power and Other
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Marketing and Trading
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Pipelines
Disaggregation of revenue
Revenue from customers	0	0
Midstream Segment | Other International | Power and Other
Disaggregation of revenue
Revenue from customers	$ 0	$ 0