Revenue Recognition - Disaggregation of revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of revenue
Revenue from customers	$ 5,687	$ 5,216	$ 14,111	$ 13,062
Consolidated	5,231	4,257	12,397	11,813
United States
Disaggregation of revenue
Consolidated	4,420	2,928	9,480	8,501
Middle East
Disaggregation of revenue
Consolidated	908	1,281	2,965	3,226
Latin America
Disaggregation of revenue
Consolidated	218	252	657	713
Other International
Disaggregation of revenue
Consolidated	53	21	90	59
Eliminations
Disaggregation of revenue
Revenue from customers	(368)	(225)	(795)	(686)
Consolidated	(368)	(225)	(795)	(686)
Eliminations | United States
Disaggregation of revenue
Revenue from customers	0	0	0	0
Eliminations | Middle East
Disaggregation of revenue
Revenue from customers	0	0	0	0
Eliminations | Latin America
Disaggregation of revenue
Revenue from customers	0	0	0	0
Eliminations | Other International
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas
Disaggregation of revenue
Revenue from customers	3,746	2,889	8,815	7,874
Oil and Gas | Oil
Disaggregation of revenue
Revenue from customers	3,313	2,539	7,895	6,961
Oil and Gas | NGL
Disaggregation of revenue
Revenue from customers	240	216	535	531
Oil and Gas | Gas
Disaggregation of revenue
Revenue from customers	208	132	427	371
Oil and Gas | Other
Disaggregation of revenue
Revenue from customers	(15)	2	(42)	11
Oil and Gas | United States
Disaggregation of revenue
Revenue from customers	2,737	1,515	5,584	4,397
Oil and Gas | United States | Oil
Disaggregation of revenue
Revenue from customers	2,453	1,326	5,105	3,907
Oil and Gas | United States | NGL
Disaggregation of revenue
Revenue from customers	177	139	339	339
Oil and Gas | United States | Gas
Disaggregation of revenue
Revenue from customers	125	47	180	141
Oil and Gas | United States | Other
Disaggregation of revenue
Revenue from customers	(18)	3	(40)	10
Oil and Gas | Middle East
Disaggregation of revenue
Revenue from customers	827	1,173	2,693	2,918
Oil and Gas | Middle East | Oil
Disaggregation of revenue
Revenue from customers	683	1,016	2,266	2,507
Oil and Gas | Middle East | NGL
Disaggregation of revenue
Revenue from customers	63	77	196	192
Oil and Gas | Middle East | Gas
Disaggregation of revenue
Revenue from customers	78	80	233	218
Oil and Gas | Middle East | Other
Disaggregation of revenue
Revenue from customers	3	0	(2)	1
Oil and Gas | Latin America
Disaggregation of revenue
Revenue from customers	182	201	538	559
Oil and Gas | Latin America | Oil
Disaggregation of revenue
Revenue from customers	177	197	524	547
Oil and Gas | Latin America | NGL
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Latin America | Gas
Disaggregation of revenue
Revenue from customers	5	5	14	12
Oil and Gas | Latin America | Other
Disaggregation of revenue
Revenue from customers	0	(1)	0	0
Oil and Gas | Other International
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Other International | Oil
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Other International | NGL
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Other International | Gas
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Other International | Other
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Eliminations
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Eliminations | Oil
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Eliminations | NGL
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Eliminations | Gas
Disaggregation of revenue
Revenue from customers	0	0	0	0
Oil and Gas | Eliminations | Other
Disaggregation of revenue
Revenue from customers	0	0	0	0
Chemical
Disaggregation of revenue
Revenue from customers	1,061	1,184	3,109	3,507
Chemical | United States
Disaggregation of revenue
Revenue from customers	1,009	1,112	2,937	3,294
Chemical | Middle East
Disaggregation of revenue
Revenue from customers	0	0	0	0
Chemical | Latin America
Disaggregation of revenue
Revenue from customers	36	51	119	154
Chemical | Other International
Disaggregation of revenue
Revenue from customers	16	21	53	59
Chemical | Eliminations
Disaggregation of revenue
Revenue from customers	0	0	0	0
Marketing and Other Midstream
Disaggregation of revenue
Revenue from customers	409	409		1,118
Marketing and Other Midstream | Gas Processing
Disaggregation of revenue
Revenue from customers	174	256	574	724
Marketing and Other Midstream | Pipelines
Disaggregation of revenue
Revenue from customers		115	311	310
Marketing and Other Midstream | Power and Other
Disaggregation of revenue
Revenue from customers	235	38	885	84
Marketing and Other Midstream | United States
Disaggregation of revenue
Revenue from customers	291	301		810
Marketing and Other Midstream | United States | Gas Processing
Disaggregation of revenue
Revenue from customers	93	148	302	416
Marketing and Other Midstream | United States | Pipelines
Disaggregation of revenue
Revenue from customers		115	274	310
Marketing and Other Midstream | United States | Power and Other
Disaggregation of revenue
Revenue from customers	198	38	576	84
Marketing and Other Midstream | Middle East
Disaggregation of revenue
Revenue from customers	81	108		308
Marketing and Other Midstream | Middle East | Gas Processing
Disaggregation of revenue
Revenue from customers	81	108	272	308
Marketing and Other Midstream | Middle East | Pipelines
Disaggregation of revenue
Revenue from customers		0	0	0
Marketing and Other Midstream | Middle East | Power and Other
Disaggregation of revenue
Revenue from customers	0	0	272	0
Marketing and Other Midstream | Latin America
Disaggregation of revenue
Revenue from customers	0	0		0
Marketing and Other Midstream | Latin America | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0	0	0
Marketing and Other Midstream | Latin America | Pipelines
Disaggregation of revenue
Revenue from customers		0	0	0
Marketing and Other Midstream | Latin America | Power and Other
Disaggregation of revenue
Revenue from customers	0	0	0	0
Marketing and Other Midstream | Other International
Disaggregation of revenue
Revenue from customers	37	0		0
Marketing and Other Midstream | Other International | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0	0	0
Marketing and Other Midstream | Other International | Pipelines
Disaggregation of revenue
Revenue from customers		0	37	0
Marketing and Other Midstream | Other International | Power and Other
Disaggregation of revenue
Revenue from customers	37	0	37	0
Marketing and Other Midstream | Eliminations
Disaggregation of revenue
Revenue from customers	0	0		0
Marketing and Other Midstream | Eliminations | Gas Processing
Disaggregation of revenue
Revenue from customers	0	0	0	0
Marketing and Other Midstream | Eliminations | Pipelines
Disaggregation of revenue
Revenue from customers		0	0	0
Marketing and Other Midstream | Eliminations | Power and Other
Disaggregation of revenue
Revenue from customers	0	$ 0	0	$ 0
WES Midstream
Disaggregation of revenue
Revenue from customers	383		383
WES Midstream | United States
Disaggregation of revenue
Revenue from customers	383		383
WES Midstream | Middle East
Disaggregation of revenue
Revenue from customers	0		0
WES Midstream | Latin America
Disaggregation of revenue
Revenue from customers	0		0
WES Midstream | Other International
Disaggregation of revenue
Revenue from customers	0		0
WES Midstream | Eliminations
Disaggregation of revenue
Revenue from customers	$ 0		$ 0