Property, Plant And Equipment (Tables)

9 Months Ended

Sep. 30, 2014

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

	September 30, 2014			December 31, 2013
	(in thousands)
Oil and gas properties
Subject to depletion	$	5,635,307		$	5,687,557
Unevaluated costs	218,398			221,605
Accumulated depletion	(5,245,133		)	(5,268,719		)
Net oil and gas properties	608,572			640,443
Other property and equipment
Pipelines and processing facilities	332,710			347,093
General properties	71,049			72,125
Accumulated depreciation	(199,851		)	(198,856		)
Net other property and equipment	203,908			220,362
Property, plant and equipment, net of accumulated depletion and depreciation	$	812,480		$	860,805