Decommissioning Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Summary of the activity for the Company's decommissioning liabilities
Decommissioning liabilities, December 31, 2014 and 2013, respectively	$ 88,000	$ 83,519
Liabilities acquired and incurred	1,176	797
Accretion	2,418	2,344
Revision estimated liabilities	1,482	(1,040)
Total decommissioning liabilities, June 30, 2015 and 2014, respectively	93,076	$ 85,620
Long-term decommissioning liabilities	$ 93,076		$ 88,000