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General (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended			6 Months Ended
General (Details) - USD ($) $ in Millions	May 31, 2020	Apr. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2017	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Noncontrolling Interest [Line Items]
Anadarko acquisition-related costs			$ (149)	$ (50)		$ (297)	$ (50)
Impairment and related charges			8,600
Income taxes paid						281	544
Domestic tax refunds						96	2
Interest paid						775	199
Cash and cash equivalents			1,011			1,011		$ 3,032
Restricted cash and restricted cash equivalents			124			124		485
Restricted cash and restricted cash equivalents included in long-term receivables and other assets, net			78			78
Cash, cash equivalents, restricted cash and restricted cash equivalents			1,213	$ 1,751		1,213	$ 1,751	3,574	$ 3,033
Equity method investment amounts			6,128			6,128		6,389
WES Midstream segment
Noncontrolling Interest [Line Items]
Equity method investment amounts			4,900			4,900		$ 5,100
Impairment of equity method investment						440
WES
Noncontrolling Interest [Line Items]
Sales			6			119
WES \| Purchases
Noncontrolling Interest [Line Items]
Purchases			92			311
WES \| Transportation, gathering and other fees paid
Noncontrolling Interest [Line Items]
Purchases			236			546
Algeria Africa Assets \| Discontinued Operations, Disposed of by Sale
Noncontrolling Interest [Line Items]
Impairment and related charges		$ 931
Ghana Assets
Noncontrolling Interest [Line Items]
Impairment and related charges			1,400			1,400
Ghana Assets \| Discontinued Operations, Held-for-sale
Noncontrolling Interest [Line Items]
Impairment and related charges	$ 1,400		2,200
Anadarko
Noncontrolling Interest [Line Items]
Anadarko acquisition-related costs			$ (149)			(297)
Domestic tax refunds					$ 881	$ 881