Net Loss per Common Share Applicable to Common Stockholders - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total antidilutive securities			80,016,676	85,807,964
Preferred stock dividends	$ 118,000	$ 2,030,000	$ 303,000	$ 2,309,000
Series E preferred stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock dividends	118,000
Series D and E Preferred Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock dividends		280,000	303,000	559,000
Loss on extinguishment of convertible preferred stock		$ 1,750,000		$ 1,750,000
Series D preferred stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Preferred stock conversion date			Feb. 06, 2014