PROPERTIES AND EQUIPMENT Properties and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Proved Natural Gas and Crude Oil Properties	$ 1,781,681	$ 2,075,924
Unproved Natural Gas and Crude Oil Properties	307,203	319,327
Total Natural Gas and Crude Oil Properties	2,088,884	2,395,251
Pipelines and Related Facilities	21,781	47,786
Transportation and Other Equipment	29,246	34,858
Land and Buildings	13,617	14,935
Construction in Progress	53,810	67,217
Gross Propertis and Equipment	2,207,338	2,560,047
Accumulated Depreciation, Depletion and Amortization	(553,893)	(943,341)
Property, Plant and Equipment, Net	$ 1,653,445	$ 1,616,706