Segment Disclosures - Geographic Information (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Geographic Information
Revenue from contracts with customers		$ 18,784,000,000		$ 32,567,000,000	$ 36,417,000,000
Long-Lived Assets	[1]	47,603,000,000		50,722,000,000	55,038,000,000
US
Geographic Information
Revenue from contracts with customers		13,230,000,000		21,159,000,000	22,740,000,000
Long-Lived Assets	[1]	24,034,000,000	[2]	26,566,000,000	26,838,000,000
Australia and Timor-Leste
Geographic Information
Revenue from contracts with customers		605,000,000		1,647,000,000	1,798,000,000
Long-Lived Assets	[1]	6,676,000,000	[3]	7,228,000,000	9,301,000,000
Canada [Member]
Geographic Information
Revenue from contracts with customers		1,261,000,000		1,769,000,000	2,024,000,000
Long-Lived Assets	[1]	6,385,000,000		5,769,000,000	5,333,000,000
CHINA
Geographic Information
Revenue from contracts with customers		460,000,000		772,000,000	836,000,000
Long-Lived Assets	[1]	1,491,000,000		1,447,000,000	1,380,000,000
INDONESIA
Geographic Information
Revenue from contracts with customers		689,000,000		875,000,000	886,000,000
Long-Lived Assets	[1]	464,000,000		605,000,000	669,000,000
Libya
Geographic Information
Revenue from contracts with customers		155,000,000		1,103,000,000	1,142,000,000
Long-Lived Assets	[1]	670,000,000		668,000,000	679,000,000
MALAYSIA
Geographic Information
Revenue from contracts with customers		610,000,000		1,230,000,000	1,346,000,000
Long-Lived Assets	[1]	1,501,000,000		1,871,000,000	2,327,000,000
NORWAY
Geographic Information
Revenue from contracts with customers		1,426,000,000		2,349,000,000	2,886,000,000
Long-Lived Assets	[1]	5,294,000,000		5,258,000,000	5,582,000,000
UNITED KINGDOM
Geographic Information
Revenue from contracts with customers		336,000,000		1,649,000,000	2,606,000,000
Long-Lived Assets	[1]	1,000,000		2,000,000	1,583,000,000
Segment Geographical Groups of Countries Other [Member]
Geographic Information
Revenue from contracts with customers		12,000,000		14,000,000	153,000,000
Long-Lived Assets	[1]	$ 1,087,000,000		$ 1,308,000,000	$ 1,346,000,000

[1] <div>(2)Defined as net PP&E plus equity investments and advances to affiliated companies.</div>

[2] <div>(3)Long-lived assets do not include $426 million of net PP&E associated with assets held for sale as of December 31, 2019. See Note 5—Acquisitions and Dispositions, for additional information.</div>

[3] <div>(4)Long-lived assets do not include $1,236 million of net PP&E associated with assets held for sale as of December 31, 2019. See Note 5—Acquisitions and Dispositions, for additional information.</div>