Properties and Equipment, Net (Tables)

9 Months Ended

Sep. 30, 2016

Property, Plant and Equipment [Abstract]

Schedule of properties and equipment, net

Properties and equipment, net are comprised of the following:

(In thousands)	September 30, 2016			December 31, 2015
Proved oil and gas properties	$	7,669,157		$	8,821,146
Unproved oil and gas properties	287,007			390,434
Gathering and pipeline systems	189,393			243,672
Land, building and other equipment	81,537			117,848
	8,227,094			9,573,100
Accumulated depreciation, depletion and amortization	(3,504,496		)	(4,596,221		)
	$	4,722,598		$	4,976,879