Equity Instruments - Schedule of Option Activity (Detail) (Stock Option [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
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	300,000
Share-based compensation arrangement by share-based payment award, options, outstanding, beginning balance	6,428,000	6,618,000	8,755,400	8,795,400	6,618,000	8,795,400	8,795,400
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average exercise price, beginning balance	$ 0.31	$ 0.32	$ 0.33	$ 0.33	$ 0.32	$ 0.33	$ 0.33
Forfeited or expired, shares	(185,000)	(190,000)	(119,500)	(40,000)
Options Outstanding, Shares, Ending balance	6,543,000	6,428,000	8,635,900	8,755,400	6,543,000	8,635,900	6,618,000	8,795,400
Options Exercisable, Shares, Ending balance	6,196,334		7,978,000		6,196,334	7,978,000
Weighted-average exercise price, granted	$ 0.25
Weighted-average exercise price Forfeited or expired	$ 0.38	$ 0.79	$ 0.35	$ 0.38
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average exercise price, ending balance	$ 0.31	$ 0.31	$ 0.33	$ 0.33	$ 0.31	$ 0.33	$ 0.32	$ 0.33
Share-based compensation arrangement by share-based payment award, weighted average exercise price, ending balance	$ 0.31		$ 0.33		$ 0.31	$ 0.33
Weighted-average remaining contractual term outstanding beginning balance		8 years 1 month 24 days		7 years 5 months 27 days	7 years 10 months 10 days	7 years 2 months 27 days	8 years 3 months 15 days	7 years 8 months 27 days
Weighted-average remaining contractual term exercisable ending					7 years 10 months 10 days	7 years 1 month 24 days