Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Recurring basis
Liabilities:
Total fair value, net	$ 237,145	$ 251,696
Recurring basis | Commodity derivatives
Assets:
Derivative asset, fair value	241,837	252,485
Liabilities:
Derivative liability, fair value	(4,196)
Recurring basis | Interest rate contracts
Assets:
Derivative asset, fair value	659
Liabilities:
Derivative liability, fair value	(1,155)	(789)
Recurring basis | Level 2
Liabilities:
Total fair value, net	237,145	251,696
Recurring basis | Level 2 | Commodity derivatives
Assets:
Derivative asset, fair value	241,837	252,485
Liabilities:
Derivative liability, fair value	(4,196)
Recurring basis | Level 2 | Interest rate contracts
Assets:
Derivative asset, fair value	659
Liabilities:
Derivative liability, fair value	(1,155)	(789)
Carrying Value
Liabilities:
Long-term debt	900,186	794,269
Total Fair Value
Liabilities:
Long-term debt	$ 823,612	$ 755,000