Changes in Property and Equipment of Continuing Operations (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	$ 3,209,643
Additions	592,677
Depreciation	(254,602)	(282,772)
Ending Balance	3,547,718
Property and equipment in service, gross
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	31,295,376
Transfers	400,729
Ending Balance	31,696,105
Accumulated depreciation
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	(28,837,522)
Depreciation	(254,602)
Ending Balance	(29,092,124)
Construction in Progress | Plant equipment & other
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	751,789
Additions	592,677
Transfers	(400,729)
Ending Balance	$ 943,737