Segment Information - Net Properties and Equipment by Geographic Area Table (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net properties and equipment		$ 27,451	$ 32,168	$ 33,751
Capitalized costs		525	1,230	$ 1,124	$ 1,522
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net properties and equipment		24,382	28,024
Algeria [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net properties and equipment		965	1,117
Other International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net properties and equipment	[1]	2,104	$ 3,027
Tubarão Tigre Discovery [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Capitalized costs		$ 413

[1] Includes $413 million of capitalized costs related to the Mozambique LNG project at December 31, 2017.