Revenue (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 1,947	$ 1,287
Other operating revenues	(49)	67
Total sales and other operating revenues	1,898	1,354
Crude oil revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,204	732
Natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	143	49
Natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	279	181
Sales of purchased oil and gas
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	321	325
Exploration and Production
Disaggregation of Revenue [Line Items]
Total sales and other operating revenues	1,898	1,354
Exploration and Production | Crude oil revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,204	732
Exploration and Production | Crude oil revenue | United States
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	885	656
Exploration and Production | Crude oil revenue | Guyana
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	181	38
Exploration and Production | Crude oil revenue | Malaysia & JDA
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	22	2
Exploration and Production | Crude oil revenue | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	116	36
Exploration and Production | Natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	143	49
Exploration and Production | Natural gas liquids revenue | United States
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	143	49
Exploration and Production | Natural gas liquids revenue | Guyana
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Exploration and Production | Natural gas liquids revenue | Malaysia & JDA
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Exploration and Production | Natural gas liquids revenue | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Exploration and Production | Natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	279	181
Exploration and Production | Natural gas revenue | United States
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	113	38
Exploration and Production | Natural gas revenue | Guyana
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Exploration and Production | Natural gas revenue | Malaysia & JDA
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	163	139
Exploration and Production | Natural gas revenue | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3	4
Exploration and Production | Sales of purchased oil and gas
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	321	325
Exploration and Production | Sales of purchased oil and gas | United States
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	298	324
Exploration and Production | Sales of purchased oil and gas | Guyana
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	4	1
Exploration and Production | Sales of purchased oil and gas | Malaysia & JDA
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Exploration and Production | Sales of purchased oil and gas | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	19	0
Midstream
Disaggregation of Revenue [Line Items]
Total sales and other operating revenues	0	0
Midstream | Crude oil revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Midstream | Natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Midstream | Natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Midstream | Sales of purchased oil and gas
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Exploration and Production
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,947	1,287
Other operating revenues	(49)	67
Total sales and other operating revenues	1,898	1,354
Operating Segments | Exploration and Production | United States
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,439	1,067
Other operating revenues	(41)	55
Total sales and other operating revenues	1,398	1,122
Operating Segments | Exploration and Production | Guyana
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	185	39
Other operating revenues	(4)	6
Total sales and other operating revenues	181	45
Operating Segments | Exploration and Production | Malaysia & JDA
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	185	141
Other operating revenues	0	1
Total sales and other operating revenues	185	142
Operating Segments | Exploration and Production | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	138	40
Other operating revenues	(4)	5
Total sales and other operating revenues	134	45
Operating Segments | Midstream
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	289	291
Other operating revenues	0	0
Total sales and other operating revenues	289	291
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(289)	(291)
Other operating revenues	0	0
Total sales and other operating revenues	(289)	(291)
Eliminations | Exploration and Production
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Total sales and other operating revenues	0	0
Eliminations | Exploration and Production | United States
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Exploration and Production | Guyana
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Exploration and Production | Malaysia & JDA
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Exploration and Production | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Midstream
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	289	291
Total sales and other operating revenues	$ 289	$ 291