Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Number of Shares Issuable
Balance, Beginning	5,886,261	3,488,761
Granted	300,000	2,597,500
Exercised	0	0
Cancelled	(476,136)	(200,000)
Balance, Ending	5,710,125	5,886,261
Weighted-average exercise price
Balance, Beginning	$ 1.11	$ 1.02
Granted	$ 0.72	$ 1.26
Exercised	$ 0	$ 0
Cancelled	$ 1.15	$ 1.40
Balance, Ending	$ 1.10	$ 1.11