Properties and Equipment, Net (Tables)

3 Months Ended

Mar. 31, 2016

Property, Plant and Equipment [Abstract]

Schedule of properties and equipment, net

Properties and equipment, net are comprised of the following:

(In thousands)	March 31, 2016			December 31, 2015
Proved oil and gas properties	$	7,483,181		$	8,821,146
Unproved oil and gas properties	324,488			390,434
Gathering and pipeline systems	242,962			243,672
Land, building and other equipment	114,596			117,848
	8,165,227			9,573,100
Accumulated depreciation, depletion and amortization	(3,327,413		)	(4,596,221		)
	$	4,837,814		$	4,976,879