Stockholders' Equity/(Deficit) - Summary of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity [Abstract]
Number of Shares, Outstanding, Beginning	3,420,154	3,399,405	3,537,236
Number of Shares, Granted	1,233,822	771,969	633,835
Number of Shares, Exercised	(204,500)	(15,150)
Number of Shares, Cancelled	(1,453,600)	(736,070)	(771,666)
Number of Shares, Outstanding, Ending	2,995,876	3,420,154	3,399,405
Weighted Average Exercise Price Outstanding, Beginning	$ 3.31	$ 3.78	$ 3.78
Number of Shares, Options exercisable	2,118,903	2,754,227	2,926,930
Weighted Average Exercise Price, Granted	$ 2.99	$ 2.85	$ 2.74
Weighted Average Exercise Price, Exercised	$ 2.24	$ 2.61
Weighted Average Exercise Price, Cancelled	$ 3.61	$ 4.42	$ 3.50
Weighted Average Exercise Price, Outstanding, Ending	$ 3.31	$ 3.31	$ 3.78
Weighted Average Exercise Price, Options exercisable	$ 2.94	$ 3.44	$ 3.79