Employee Stock Purchase Plan (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Shares
Outstanding, beginning of period	2,302,000	2,228,067
Stock options granted	200,000	0
Stock options exercised	(2,000)	0
Restricted stock exercised	(2,500)	(2,500)
Canceled/Expired	(62,000)	(89,900)
Outstanding, end of period	2,435,500	2,135,667
Exercisable, end of period	1,371,725	1,346,767
Weighted Avg Exercise Price
Outstanding, beginning of period	$ 1.06	$ 1.14
Stock options granted	$ 0.29	$ 0
Stock options exercised	$ 0.12	$ 0
Restricted stock exercised	0	0
Canceled/Expired	$ 1.89	$ 0.62
Outstanding, end of period	$ 0.98	$ 1.16
Exercisable, end of period	$ 1.43	$ 1.51