Property, Plant and Equipment - Capitalized Exploratory Well Costs - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) km² Well	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Capitalized Exploratory Well Costs [Line Items]
Expenses on capitalized exploratory well costs associated with project	$ 597	$ 1,415	$ 1,416	$ 2,045
Exploratory dry hole costs which were incurred and subsequently expensed	167	$ 54	$ 66
Capitalized exploratory well costs that have been capitalized for period greater than one year	511
Non-operated Sicily Project And Melmar Project, Gulf of Mexico
Capitalized Exploratory Well Costs [Line Items]
Expenses on capitalized exploratory well costs associated with project	$ 830
Deepwater Tano/Cape Three Points License, Offshore Ghana
Capitalized Exploratory Well Costs [Line Items]
Capitalized well costs percentage	55.00%
Percentage of ownership interest on license	50.00%
This number of approved appraisal wells is completed | Well	3
Stabroek Block, Offshore Guyana
Capitalized Exploratory Well Costs [Line Items]
Capitalized well costs percentage	20.00%
Participating interest rate on exploration well	30.00%
Area of exploratory well completed | km²	17,000
Northern Portion of Shenzi Field, Gulf of Mexico
Capitalized Exploratory Well Costs [Line Items]
Capitalized well costs percentage	20.00%
Participating interest rate on exploration well	28.00%
JDA, Gulf of Thailand
Capitalized Exploratory Well Costs [Line Items]
Capitalized well costs percentage	5.00%