Asset Retirement Obligations

6 Months Ended

Jun. 30, 2015

Asset Retirement Obligation Disclosure [Abstract]

(9) ASSET RETIREMENT OBLIGATIONS

Our asset retirement obligations primarily represent the estimated present value of the amounts we will incur to plug, abandon and remediate our producing properties at the end of their productive lives. Significant inputs used in determining such obligations include estimates of plugging and abandonment costs, estimated future inflation rates and well lives. The inputs are calculated based on historical data as well as current estimated costs. In the first six months 2015, we increased our estimated abandonment costs on certain of our water impoundments and changed estimated well lives for certain wells in Pennsylvania. A reconciliation of our liability for plugging and abandonment costs for the six months ended June 30, 2015 is as follows (in thousands):

	Six Months Ended June 30, 2015
Beginning of period	$	287,463
Liabilities incurred		2,994
Liabilities settled		(7,410	)
Disposition of wells		(4,115	)
Accretion expense		9,570
Change in estimate		15,690
End of period		304,192
Less current portion		17,689
Long-term asset retirement obligations	$	286,503

Accretion expense is recognized as a component of depreciation, depletion and amortization expense in the accompanying consolidated statements of consolidated operations.