Property and Equipment - Additional Information (Detail) (USD $)	12 Months Ended		119 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012
Property, Plant, and Equipment Disclosure [Line Items]
Depreciation expense	$ 303,677	$ 210,252	$ 1,650,158
Minimum
Property, Plant, and Equipment Disclosure [Line Items]
Property, plant and equipment, useful life	3 years
Maximum
Property, Plant, and Equipment Disclosure [Line Items]
Property, plant and equipment, useful life	10 years