Equity Instruments - Schedule of Warrant Activity (Detail) (Common Stock [Member], Warrant [Member], USD $)	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Common Stock [Member] | Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding shares beginning balance	37,332,583	35,957,583	40,982,583	41,057,583	35,957,583	41,057,583	41,057,583
Shares granted	2,010,000	1,700,000		25,000
Forfeited or expired shares		(325,000)	(2,300,000)	(100,000)
Shares cancelled	(2,000,000)
Warrants outstanding shares ending balance	37,342,583	37,332,583	38,682,583	40,982,583	37,342,583	38,682,583	35,957,583	41,057,583
Weighted average exercise price beginning balance	$ 0.33	$ 0.33	$ 0.35	$ 0.35	$ 0.33	$ 0.35	$ 0.35
Warrants exercisable shares	37,308,583		37,615,583		37,308,583	37,615,583
Weighted-average exercise price granted	$ 0.20	$ 0.25		$ 0.25
Weighted-average exercise price forfeited or expired		$ 0.37	$ 0.32	$ 0.53
Weighted-average exercise price cancelled	$ 0.20
Weighted average exercise price ending balance	$ 0.33	$ 0.33	$ 0.35	$ 0.35	$ 0.33	$ 0.35	$ 0.33	$ 0.35
Weighted average exercise, exercisable price	$ 0.33		$ 0.33		$ 0.33	$ 0.33
Weighted-average remaining contractual term outstanding beginning balance		4 years		4 years 7 months 10 days	3 years 9 months	4 years 6 months 29 days	4 years 3 months 4 days	4 years 10 months 10 days
Weighted average remaining contractual term exercisable					3 years 9 months	4 years 7 months 13 days