Investments - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 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 method accretion adjustments	21
Equity Investment Adjustments	31
Excess carrying value of investment over underlying equity in net assets	23
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity Attributable to Goodwill	14
Sundrop Fuels Inc [Member]
Schedule of Equity Method Investments [Line Items]
Equity Investment Adjustments	4
Excess carrying value of investment over underlying equity in net assets	83
Interest Costs Capitalized	$ 5
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