Commitments and Contingencies Commitments and Contingencies (Details) MMcf in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) MMcf MMBbls	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) MMcf MMBbls	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) MMcf
Water Disposal Agreement [Member]
Other Commitments [Line Items]
Water Delivery Commitments and Contracts, Remaining Contractual Volume | MMBbls	25,400,000		25,400,000
Contractual Obligation	$ 23.0		$ 23.0
Drilling Rig Leasing Contracts [Member]
Other Commitments [Line Items]
Gain (Loss) on Contract Termination	(2.6)	$ (2.7)	(7.6)	$ (5.9)
Gas gathering and Oil and Gas Through-put Commitments [Member]
Other Commitments [Line Items]
Contractual Obligation, Amended Gathering Agreements Related to Non-Operated Eagle Ford Assets	342.0		342.0
Contractual Payments Receivable, Amended Gathering Agreements Related to Non-Operated Eagle Ford Assets	241.4		241.4
Decrease in Contractual Obligation					$ 118.2
Contractual Obligation	$ 1,000.0		$ 1,000.0
Crude Oil Transportation Commitment [Member]
Other Commitments [Line Items]
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume on Amended Gathering Agreements Related to Non-Operated Eagle Ford Assets | MMBbls	39		39
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume | MMBbls	72		72
Natural Gas Transportation Commitment [Member]
Other Commitments [Line Items]
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume on Amended Gathering Agreements Related to Non-Operated Eagle Ford Assets | MMcf	296		296
Oil and Gas Delivery Commitments and Contracts, Decrease in Remaining Contractual Volume | MMcf					829
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume | MMcf	1,590		1,590
Natural Gas Liquids Transportation Commitment [Member]
Other Commitments [Line Items]
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume | MMBbls	14		14