Net Loss per Common Share Applicable to Common Stockholders - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total antidilutive securities			87,624,124	16,021,649
Preferred stock extinguishment loss and dividends	$ 278,000	$ 160,000	$ 2,587,000	$ 480,000
Series D and E Preferred Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock extinguishment loss and dividends	278,000		837,000
Loss on extinguishment of convertible preferred stock			1,750,000
Series D Convertible Redeemable Preferred Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock extinguishment loss and dividends		$ 160,000		$ 480,000