Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Preferred Financing [Member]	Dec. 31, 2010 Preferred Financing [Member]	Dec. 31, 2012 Change in Control [Member]	Sep. 22, 2006 Change in Control [Member]
Income Taxes [Line Items]
Net operating loss carryforward annual limitation			$ 591,000		$ 8,135,000
Net operating loss carryforward expected to expire			6,025,000
Net operating loss expired			13,324,000
Decrease in related valuation allowance			(1,503,000)
Net operating loss additional amount utilizable				4,044,000
Reversed portion of the valuation allowance related adjustment				1,375,000
Three-year cumulative percentage of company's common stock traded by large shareholders						50.00%
Deductions taken for tax purposes on stock option exercises	171,000	3,275,000
Tax benefit due to a change in tax law	$ 1,300,000