Commitments (Details) MMcf in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2016 USD ($) MMBbls MMcf	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Commitments and Contingencies
Contractual Obligation, Due in Next Twelve Months	[1]	$ 145,075
Contractual Obligation, Due in Second Year	[1]	148,240
Contractual Obligation, Due in Third Year	[1]	144,379
Contractual Obligation, Due in Fourth Year	[1]	141,010
Contractual Obligation, Due in Fifth Year	[1]	141,654
Contractual Obligation, Due after Fifth Year	[1]	337,745
Contractual Obligation	[1]	1,058,103
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals		2,700
Operating Leases, Rent Expense		$ 5,200	$ 6,100	$ 6,500
Natural Gas Transportation Commitment [Member]
Commitments and Contingencies
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume | MMcf		1,461
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume on Non-Operated Eagle Ford Assets | MMcf		514
Crude Oil Transportation Commitment [Member]
Commitments and Contingencies
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume | MMBbls		70
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume on Non-Operated Eagle Ford Assets | MMBbls		52
Natural Gas Liquids Transportation Commitment [Member]
Commitments and Contingencies
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume | MMBbls		13
Oil and Gas Delivery Commitments and Contracts, Remaining Contractual Volume on Non-Operated Eagle Ford Assets | MMBbls		13
Drilling Rig Leasing Contracts [Member]
Commitments and Contingencies
Contractual Obligation		$ 31,100
Early Termination Penalty For Rig Contract Cancellation		14,200
Gain (Loss) on Contract Termination		$ (8,700)	$ (13,700)
Water Transportation Commitment [Member]
Commitments and Contingencies
Water Delivery Commitments and Contracts, Remaining Contractual Volume | MMBbls		25
Gas Gathering and Oil, Gas, NGL, and Water Through-put Commitments [Member]
Commitments and Contingencies
Contractual Obligation		$ 970,900
Contractual Obligation, Non-Operated Eagle Ford Assets		501,900
Office Space Leases [Member]
Commitments and Contingencies
Contractual Obligation		50,100
Gain (Loss) on Contract Termination		(3,200)
Other miscellaneous contracts and leases [Member]
Commitments and Contingencies
Contractual Obligation		$ 6,000

[1] During the third quarter of 2015, the Company closed its office in Tulsa, Oklahoma. These amounts include lease payments for the Tulsa office, net of sublease income. The Company expects to receive $2.7 million of total sublease income through 2019.