Summary of Significant Accounting Policies (Details 3) - USD ($)	12 Months Ended			36 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015
Other Property and Equipment
Depreciation expense	$ 709,763,000	$ 477,896,000	$ 233,876,000
Oil and Gas Properties
Exploratory drilling costs initially capitalized, but subsequently charged to expense	0	0	0
Impairment of unproved properties for leases expired or expected to expire	104,300,000	15,200,000	10,900,000
Impairment of proved properties	$ 0	0	0
Period of deferment of significant costs, pending proved reserves	1 year
Depreciation, depletion, and amortization expense for oil and gas properties	$ 614,700,000	418,700,000	219,800,000
Impairment of long-lived assets other than oil and gas properties				$ 0
Deferred Financing Costs
Unamortized deferred financing costs included in other long-term assets	59,000,000			$ 59,000,000
Amounts amortized and the write-off of previously deferred debt issuance costs	$ 10,100,000	11,000,000	15,800,000
Gathering Systems and Facilities
Other Property and Equipment
Estimated useful life	P20Y
Other property and equipment
Other Property and Equipment
Depreciation expense	$ 7,700,000	5,900,000	2,200,000
Other property and equipment | Minimum
Other Property and Equipment
Estimated useful life	P2Y
Other property and equipment | Maximum
Other Property and Equipment
Estimated useful life	P20Y
Gathering pipelines, compressor stations, and fresh water distribution systems
Other Property and Equipment
Depreciation expense	$ 87,400,000	$ 53,200,000	$ 11,900,000
Water handling and treatment | Minimum
Other Property and Equipment
Estimated useful life	P5Y
Water handling and treatment | Maximum
Other Property and Equipment
Estimated useful life	P20Y