Property, Plant & Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 320,010
Accumulated Depreciation	(107,638)
Property, plant and equipment	212,372	246,586
Gas Gathering Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	282,879
Accumulated Depreciation	(99,312)
Property, plant and equipment	183,567	219,011
Computer equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	2,510
Accumulated Depreciation	(1,510)
Property, plant and equipment	1,000	1,025
Office equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	454
Accumulated Depreciation	(374)
Property, plant and equipment	80	109
Leasehold improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	450
Accumulated Depreciation	(251)
Property, plant and equipment	199	307
Land [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	22,359
Accumulated Depreciation	0
Property, plant and equipment	22,359	22,150
Other [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	11,358
Accumulated Depreciation	(6,191)
Property, plant and equipment	$ 5,167	$ 3,984