Summary of the Status of the Warrants Outstanding (Detail) (Warrant, USD $)	12 Months Ended
	Dec. 31, 2013
Share-Based Compensation Arrangement By Share-Based Payment Award [Line Items]
Number Outstanding	87,929,794
Weighted Average Remaining Contractual Life, Outstanding	3 years 1 month 20 days
Weighted Average Exercise Price, Outstanding	$ 0.15
Number Exercisable	87,929,794
Weighted Average Exercise Price, Exercisable	$ 0.15
Range of Exercise Prices - Range 1
Share-Based Compensation Arrangement By Share-Based Payment Award [Line Items]
Range of Exercise Prices, Lower	$ 0.0745
Number Outstanding	39,333,936
Weighted Average Remaining Contractual Life, Outstanding	3 years 6 months 7 days
Weighted Average Exercise Price, Outstanding	$ 0.07
Number Exercisable	39,333,936
Weighted Average Exercise Price, Exercisable	$ 0.07
Range of Exercise Prices - Range 2
Share-Based Compensation Arrangement By Share-Based Payment Award [Line Items]
Range of Exercise Prices, Lower	$ 0.08
Range of Exercise Prices, Upper	$ 0.09
Number Outstanding	19,956,065
Weighted Average Remaining Contractual Life, Outstanding	4 years 7 months 24 days
Weighted Average Exercise Price, Outstanding	$ 0.09
Number Exercisable	19,956,065
Weighted Average Exercise Price, Exercisable	$ 0.09
Range of Exercise Prices - Range 3
Share-Based Compensation Arrangement By Share-Based Payment Award [Line Items]
Range of Exercise Prices, Lower	$ 0.1287
Number Outstanding	4,222,599
Weighted Average Remaining Contractual Life, Outstanding	3 years 11 months 12 days
Weighted Average Exercise Price, Outstanding	$ 0.13
Number Exercisable	4,222,599
Weighted Average Exercise Price, Exercisable	$ 0.13
Range of Exercise Prices - Range 4
Share-Based Compensation Arrangement By Share-Based Payment Award [Line Items]
Range of Exercise Prices, Lower	$ 0.30
Range of Exercise Prices, Upper	$ 0.35
Number Outstanding	24,417,194
Weighted Average Remaining Contractual Life, Outstanding	1 year 1 month 20 days
Weighted Average Exercise Price, Outstanding	$ 0.31
Number Exercisable	24,417,194
Weighted Average Exercise Price, Exercisable	$ 0.31