Manufactured Methane (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Methane Project [Line Items]
Depreciation expense	$ 30,000	$ 82,000
Methane Project [Member]
Methane Project [Line Items]
Date methane facilities were placed into service	Apr. 01, 2009
Landfill closure date	Dec. 01, 2041
Methane facilities estimated useful life	33 years