Investments - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Proceeds from sales of investments	$ 0	$ 239
FTS International, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Equity Investment Adjustments	72
Equity method accretion adjustments	44
Sundrop Fuels Inc [Member]
Schedule of Equity Method Investments [Line Items]
Equity Investment Adjustments	18
Interest Costs Capitalized	7
Excess carrying value of investment over underlying equity in net assets	$ 85
Chaparral Energy Inc [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from sales of investments		209
Equity Method Investment, Realized Gain (Loss) on Disposal		73
Other Investments [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from sales of investments		30
Equity Method Investment, Realized Gain (Loss) on Disposal		$ 6