Property, Plant and Equipment-Net - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	May 31, 2011 Manufacturing Facility l Mg	May 31, 2011 Manufacturing Facility Promissory note
Property, Plant and Equipment [Line Items]
Capitalized interest	$ 300,000	$ 0	$ 0
Depreciation and amortization expense	3,519,000	1,707,000	786,000
Fermenters production facility				128,000
Annual oil production capacity, in units				2,000,000
Annual oil production capacity				1,820
Purchase price of production facility				11,500,000
Proceeds received from sale of equipment				300,000
Amount borrowed					5,500,000
Fair value of assets allocated to plant equipment, building and inprovements and land	$ 10,900,000