Investing Activities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019		Apr. 30, 2019
Schedule of Equity Method Investments [Line Items]
Gain on disposition of equity-method investments (1)	$ 0	$ 0	$ 0	$ 122	[1]
Other investing income (loss) - net	2	7	6	132
Equity Method Investment, Other than Temporary Impairment	0	114	938	186
Proceeds from dispositions of equity-method investments			0	485
Equity earnings (losses)	106	93	236	260
Other Income [Member]
Schedule of Equity Method Investments [Line Items]
Other investing income (loss) - net	$ 2	$ 7	6	10
Jackalope Gas Gathering Services LLC [Member]
Schedule of Equity Method Investments [Line Items]
Gain on disposition of equity-method investments (1)				122
Equity Method Investment, Ownership Percentage						50.00%
Proceeds from dispositions of equity-method investments				$ 485
Rocky Mountain Midstream Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings (losses)			$ (78)

[1] In April 2019, we sold our 50 percent equity-method interest in Jackalope for $485 million in cash, resulting in a gain on the disposition of $122 million.