Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Carrying Value
Liabilities:
Long-term debt	$ 1,204,653	$ 1,353,716
Total Fair Value
Liabilities:
Long-term debt	1,229,594	1,378,938
Recurring basis
Liabilities:
Total fair value, net	28,715	1,691
Recurring basis | Commodity derivatives
Assets:
Derivative asset, fair value	42,289	34,924
Liabilities:
Derivative liability, fair value	(14,182)	(33,286)
Recurring basis | Interest rate contracts
Assets:
Derivative asset, fair value	641	582
Liabilities:
Derivative liability, fair value	(33)	(529)
Recurring basis | Level 2
Liabilities:
Total fair value, net	28,715	1,691
Recurring basis | Level 2 | Commodity derivatives
Assets:
Derivative asset, fair value	42,289	34,924
Liabilities:
Derivative liability, fair value	(14,182)	(33,286)
Recurring basis | Level 2 | Interest rate contracts
Assets:
Derivative asset, fair value	641	582
Liabilities:
Derivative liability, fair value	(33)	(529)
Facility | Carrying Value
Liabilities:
Long-term debt	700,000	850,000
Facility | Total Fair Value
Liabilities:
Long-term debt	700,000	850,000
Senior Notes | Carrying Value
Liabilities:
Long-term debt	504,653	503,716
Senior Notes | Total Fair Value
Liabilities:
Long-term debt	$ 529,594	$ 528,938