Additional Information Regarding Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Shares	7,131,000	9,036,000	7,365,000
Options outstanding, Weighted average remaining contractual life (years)	3 years 1 month 6 days	3 years 2 months 12 days	2 years 1 month 6 days
Options outstanding, Weighted average exercise price	$ 0.65	$ 0.72	$ 0.67
Options exercisable, Shares	3,402,000
Options exercisable, Weighted average exercise price	$ 0.66
Range of exercise prices, .05 - .20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Shares	108,000
Options outstanding, Weighted average remaining contractual life (years)	4 months 24 days
Options outstanding, Weighted average exercise price	$ 0.17
Options exercisable, Shares	108,000
Options exercisable, Weighted average exercise price	$ 0.17
Range of exercise prices, .24 - .65
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Shares	2,739,000
Options outstanding, Weighted average remaining contractual life (years)	2 years 6 months
Options outstanding, Weighted average exercise price	$ 0.41
Options exercisable, Shares	1,650,000
Options exercisable, Weighted average exercise price	$ 0.39
Range of exercise prices, .67 - .88
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Shares	3,750,000
Options outstanding, Weighted average remaining contractual life (years)	4 years
Options outstanding, Weighted average exercise price	$ 0.77
Options exercisable, Shares	1,110,000
Options exercisable, Weighted average exercise price	$ 0.86
Range of exercise prices, 1.00 - 1.48
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Shares	534,000
Options outstanding, Weighted average remaining contractual life (years)	1 month 6 days
Options outstanding, Weighted average exercise price	$ 1.16
Options exercisable, Shares	534,000
Options exercisable, Weighted average exercise price	$ 1.16
Range of exercise prices, .05 - 1.48
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Shares	7,131,000
Options outstanding, Weighted average remaining contractual life (years)	3 years 1 month 6 days
Options outstanding, Weighted average exercise price	$ 0.65
Options exercisable, Shares	3,402,000
Options exercisable, Weighted average exercise price	$ 0.66