Asset Retirement Obligations (Tables)

6 Months Ended

Jun. 30, 2018

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Change in Asset Retirement Obligation

The following table presents the changes in carrying amounts of the asset retirement obligations associated with our working interests in crude oil and natural gas properties:

	Amount
	(in thousands)
Balance at December 31, 2017	$	87,306
Obligations incurred with development activities	1,517
Obligations incurred with acquisition	4,687
Accretion expense	2,573
Revisions in estimated cash flows	42
Obligations discharged with asset retirements and divestiture	(6,617		)
Balance at June 30, 2018	89,508
Current portion	(15,959		)
Long-term portion	$	73,549