Property and Equipment (Tables)

6 Months Ended

Jun. 30, 2018

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

The major categories of property and equipment and related accumulated depletion, depreciation, amortization and impairment as of June 30, 2018 and December 31, 2017 are as follows:

	June 30, 2018			December 31, 2017
	(In thousands)
Oil and natural gas properties	$	9,749,156		$	9,169,156
Office furniture and fixtures	41,822			37,369
Building	44,565			44,565
Land	4,820			4,820
Total property and equipment	9,840,363			9,255,910
Accumulated depletion, depreciation, amortization and impairment	(4,386,370		)	(4,153,733		)
Property and equipment, net	$	5,453,993		$	5,102,177

Summary of Non-producing Properties Excluded from Amortization by Area

The following table summarizes the Company’s non-producing properties excluded from amortization by area at June 30, 2018:

	June 30, 2018
	(In thousands)
Utica	$	1,538,885
MidContinent	1,417,309
Niobrara	451
Southern Louisiana	571
Bakken	99
Other	46
	$	2,957,361

Schedule of Asset Retirement Obligation

A reconciliation of the Company’s asset retirement obligation for the six months ended June 30, 2018 and 2017 is as follows:

	June 30, 2018			June 30, 2017
	(In thousands)
Asset retirement obligation, beginning of period	$	75,100		$	34,276
Liabilities incurred	909			9,505
Liabilities settled	(719		)	(344		)
Accretion expense	2,019			692
Revisions in estimated cash flows	(374		)	—
Asset retirement obligation as of end of period	76,935			44,129
Less current portion	120			195
Asset retirement obligation, long-term	$	76,815		$	43,934