Asset Retirement Obligations (Tables)

6 Months Ended

Jun. 30, 2015

Asset Retirement Obligations

Schedule of changes in the Company's ARO's

	Six Months Ended			Six Months Ended
	June 30, 2015			June 30, 2014
	(in thousands)
Asset retirement obligations — beginning of period	$	21,599		$	26,308
Liabilities incurred	2			844
Revisions	—			—
Liabilities settled	—			(47		)
Liabilities eliminated through asset sales	(4,699		)	(7,652		)
Current period accretion expense	835			929
Asset retirement obligations — end of period	$	17,737		$	20,382