Asset Retirement Obligations

12 Months Ended

Dec. 31, 2019

Asset Retirement Obligation Disclosure [Abstract]

(9)	Asset Retirement Obligations

Our asset retirement obligations (“ARO”) primarily represent the present value of the estimated 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. The following is a reconciliation of our liability for plugging and abandonment costs as of December 31, 2019 and 2018 (in thousands):


	2019			2018
Beginning of period	$	312,754		$	276,855
Liabilities incurred		4,063			3,376
Acquisitions		—			13,438
Liabilities settled		(5,953	)		(5,052	)
Disposition of wells		(82,576	)		(13,332	)
Accretion expense		15,658			25,456
Change in estimate		7,130			12,013
End of period		251,076			312,754
Less current portion		(2,393	)		(5,485	)
Long-term asset retirement obligations ^(a)	$	248,683		$	307,269

^(a) In fourth quarter 2019, we entered into an agreement to sell our legacy assets in Northwest Pennsylvania. Final approval from the state governmental authorities for a change in operatorship is expected by mid-2020, at which time we will reduce this liability by approximately $125.5 million and recognize a gain on sale of these assets.

Accretion expense is recognized as an increase to depreciation, depletion and amortization expense in the accompanying consolidated statements of operations.