Asset Retirement Obligations

6 Months Ended

Jun. 30, 2015

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

Asset Retirement Obligations

The following table is a reconciliation of the ARO liability as of and for the six months ended June 30, 2015 and the twelve months ended December 31, 2014.

	June 30, 2015		December 31, 2014
Asset retirement obligation at beginning of period	$	44,214	$	51,954
Liabilities incurred on properties acquired and developed	2,506		3,721
Revisions to previous estimates	—		(14,821		)
Accretion expense	3,828		3,360
Asset retirement obligation at end of period	$	50,548	$	44,214