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Number of warrants or rights outstanding.

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Stock-Based Compensation and Warrants - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jan. 31, 2014
Stock Based Compensation Plans [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 4,400,000
Stock-based compensation expense	91,286	86,278
Class of Warrant or Right, Exercise Price of Warrants or Rights			$ 4.74
Warrants
Stock Based Compensation Plans [Line Items]
Class of Warrant or Right, Outstanding	10,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.90
Research and Development Expense
Stock Based Compensation Plans [Line Items]
Stock-based compensation expense	28,784	6,623
Director Service Stock Option
Stock Based Compensation Plans [Line Items]
Stock-based compensation expense	$ 62,502	$ 79,655