Employee Stock Purchase Plan (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Shares
Outstanding, beginning of period	2,228,067	1,611,267
Granted	581,000	810,000
Exercised	(2,500)	(2,500)
Forfeited/Expired	(504,567)	(190,700)
Outstanding, end of period	2,302,000	2,228,067
Exercisable, end of period	1,376,950	1,099,817
Weighted Avg Exercise Price
Outstanding, beginning of period	$ 1.14	$ 1.54
Granted	$ 0.36	$ 0.34
Exercised	$ 0.00	$ 0.00
Canceled/Expired	$ 0.60	$ 1.21
Outstanding, end of period	$ 1.06	$ 1.14
Exercisable, end of period	$ 1.49	$ 1.72