Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)				3 Months Ended											12 Months Ended
	Jan. 01, 2016	Dec. 31, 2015		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014		Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014		Jan. 01, 2017	Dec. 31, 2013
Schedule Of Significant Accounting Policies [Line Items]
Total asset impairment charges															$ 1,100,000,000	$ 9,500,000,000		$ 7,100,000,000
Impairment charge of Petroleum Revenue Tax benefits, before tax															486,000,000
Inventory write-downs															55,000,000	55,000,000		32,000,000
UK Petroleum Revenue Tax (PRT) rate	0.00%	35.00%
Impairment charge of Petroleum Revenue Tax benefits, net of tax															292,000,000
Remaining recoverable Petroleum Revenue Tax benefits				$ 8,000,000											8,000,000
Goodwill impairment charges															0	163,000,000		347,000,000
Impairment of equity method investment																148,000,000
Impairment of assets held for sale and other assets																		655,000,000
Asset impairments				144,000,000	$ 951,000,000	$ 238,000,000	$ 42,000,000	$ 5,100,000,000		$ 4,100,000,000	$ 660,000,000	$ 2,100,000,000			1,103,000,000	9,472,000,000	[1],[2]	7,102,000,000	[1],[2]
Cash and cash equivalents		$ 1,467,000,000	[2],[3]	1,377,000,000				1,467,000,000	[2],[3]				$ 679,000,000	[2]	1,377,000,000	1,467,000,000	[2],[3]	679,000,000	[2]		$ 1,906,000,000	[2]
Allowance for doubtful accounts		103,000,000		93,000,000				103,000,000					98,000,000		93,000,000	103,000,000		98,000,000			$ 78,000,000
Oil and gas property, fair value		3,900,000,000		306,000,000				3,900,000,000					4,800,000,000		306,000,000	3,900,000,000		4,800,000,000
Gathering, transmission and processing facilities		1,052,000,000	[3]	976,000,000				1,052,000,000	[3]						976,000,000	1,052,000,000	[3]
Accumulated depreciation		25,312,000,000	[3]	27,882,000,000				25,312,000,000	[3]						27,882,000,000	25,312,000,000	[3]
Impairment of GTP assets															135,000,000	1,700,000,000		1,100,000,000
Fair value of GTP assets		306,000,000		142,000,000				306,000,000							142,000,000	306,000,000
Accounts payable															86,000,000	129,000,000
Net cost of third party gas															$ 159,000,000	105,000,000		70,000,000
Maximum percentage of production available to contract partners															40.00%
Other foreign currency gains and (losses)															$ (25,000,000)	(11,000,000)		8,000,000
Benefit of tax deductions in excess of recognized compensation cost															2,000,000	1,000,000		35,000
GTP Facilities [Member]
Schedule Of Significant Accounting Policies [Line Items]
Gathering, transmission and processing facilities		1,100,000,000		976,000,000				1,100,000,000							976,000,000	1,100,000,000
Accumulated depreciation		160,000,000		130,000,000				160,000,000							130,000,000	160,000,000
Gain (loss) on the sale of GTP facilities																59,000,000		(180,000,000)
Oil and Gas Properties, Proved [Member]
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment															427,000,000	7,389,000,000		6,068,000,000
Gas Gathering, Transmission, and Processing Assets [Member]
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments for property and equipment															135,000,000	1,700,000,000
Other Property and Equipment [Member]
Schedule Of Significant Accounting Policies [Line Items]
Accumulated depreciation		$ 693,000,000		$ 780,000,000				$ 693,000,000							780,000,000	693,000,000
United States [Member]
Schedule Of Significant Accounting Policies [Line Items]
Goodwill impairment charges															0	0		244,000,000
Impairment of GTP assets																103,000,000
Canada [Member]
Schedule Of Significant Accounting Policies [Line Items]
Goodwill impairment charges															0	0		103,000,000
Impairment of GTP assets																555,000,000
Egypt [Member]
Schedule Of Significant Accounting Policies [Line Items]
Goodwill impairment charges															$ 0	0		0
Impairment of GTP assets																$ 1,100,000,000
Australia [Member] | Discontinued Operations [Member]
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments																		833,000,000
Australia [Member] | Oil and Gas Properties, Proved [Member] | Discontinued Operations [Member]
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments																		271,000,000
Wheatstone LNG [Member]
Schedule Of Significant Accounting Policies [Line Items]
Impairment of GTP assets																		$ 430,000,000
Wheatstone LNG [Member] | Australia [Member]
Schedule Of Significant Accounting Policies [Line Items]
Asset impairments													$ 833,000,000
Minimum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Voting interest required for consolidation of investments				50.00%											50.00%
Minimum [Member] | Other Property and Equipment [Member]
Schedule Of Significant Accounting Policies [Line Items]
Useful lives of gas gathering, transmission and processing facilities															3 years
Maximum [Member]
Schedule Of Significant Accounting Policies [Line Items]
Voting interest required for consolidation of investments				50.00%											50.00%
Maximum [Member] | Other Property and Equipment [Member]
Schedule Of Significant Accounting Policies [Line Items]
Useful lives of gas gathering, transmission and processing facilities															20 years
Retained Earnings (Accumulated Deficit) [Member] | Subsequent Event [Member] | Accounting Standards Update 2016-09 [Member]
Schedule Of Significant Accounting Policies [Line Items]
Cumulative effect of change on equity																				$ 11,000,000

[1] Financial information for 2015 and 2014 has been recast to reflect retrospective application of the successful efforts method of accounting. See Note 1.

[2] Financial information for 2015 and 2014 has been recast to reflect retrospective application of the successful efforts method of accounting. See Note 1.

[3] Financial information for 2015 has been recast to reflect retrospective application of the successful efforts method of accounting. See Note 1.