Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 30, 2015
Property, Plant and Equipment [Line Items]
Total capitalized interest	$ 49,000,000	$ 84,000,000	$ 144,000,000
Goodwill	1,310,000,000	0		$ 779,000,000
Goodwill Impairment	$ 0	$ 0	779,000,000
Goodwill allocation			4,000,000
Goodwill fair value			0
Rosetta Merger
Property, Plant and Equipment [Line Items]
Acquired goodwill			$ 163,000,000
Minimum
Property, Plant and Equipment [Line Items]
Useful lives of gathering facilitates and processing plants (in years)	3 years
Maximum
Property, Plant and Equipment [Line Items]
Useful lives of gathering facilitates and processing plants (in years)	30 years