Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2019

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligation

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.