Properties and Equipment, Net (Tables)

3 Months Ended

Mar. 31, 2015

Property, Plant and Equipment [Abstract]

Schedule of properties and equipment, net

Properties and equipment, net are comprised of the following:

(In thousands)	March 31, 2015			December 31, 2014
Proved oil and gas properties	$	8,291,686		$	7,984,979
Unproved oil and gas properties	486,562			492,208
Gathering and pipeline systems	241,458			241,272
Land, building and other equipment	111,090			109,758
	9,130,796			8,828,217
Accumulated depreciation, depletion and amortization	(4,071,992		)	(3,902,506		)
	$	5,058,804		$	4,925,711