Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Deferred revenue	$ 1,576,186	$ 4,010,493
Basis difference in equipment	(890,387)	(926,735)
Basis difference in intangibles	(501,709)	(618,403)
Accrued liabilities and other	418,300	263,364
R&D credit	10,366,432	8,720,314
Stock options	2,199,794	1,557,756
Net operating loss carry-forward (NOL)	40,494,523	16,575,544
Gross, Deferred Tax Assets	53,663,139	29,582,333
Less: valuation allowance	(53,663,139)	(29,582,333)
Net of Valuation Allowance