Summary of Preferred Stock Terms (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Preferred stock, Liquidation value	$ 2,871,000
Preferred stock, cumulative and undeclared dividends in arrears	(266)	(266)
Series A Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Liquidation value	212,625
Preferred stock, conversion Price	$ 103.034
Preferred stock, conversion Rate	0.04367%
Preferred stock, voting Rights	None
Preferred stock, dividends	0.00%	0.00%
Preferred stock, conversion Period	Any time
Series B Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Liquidation value	375,000
Preferred stock, conversion Price	$ 10.00
Preferred stock, conversion Rate	0.40%
Preferred stock, voting Rights	None
Preferred stock, dividends	10.00%	10.00%
Preferred stock, conversion Period	Any time
Preferred stock, cumulative and undeclared dividends in arrears	445,000
Series C Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Liquidation value	115,000
Preferred stock, conversion Price	$ 6.00
Preferred stock, conversion Rate	0.50%
Preferred stock, voting Rights	None
Preferred stock, dividends	10.00%	10.00%
Preferred stock, conversion Period	Any time
Preferred stock, cumulative and undeclared dividends in arrears	128,000
Series D Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Liquidation value	1,750,000
Preferred stock, conversion Price	$ 10.00
Preferred stock, conversion Rate	1.00%
Preferred stock, voting Rights	None
Preferred stock, dividends	10.00%	10.00%
Preferred stock, conversion Period	Any time
Preferred stock, cumulative and undeclared dividends in arrears	1,955,000
Series E Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Liquidation value	418,488
Preferred stock, conversion Price	$ 8.00
Preferred stock, conversion Rate	2.75%
Preferred stock, voting Rights	Equal in all respects to holders of common shares
Preferred stock, dividends	10.00%	10.00%
Preferred stock, conversion Period	Any time
Preferred stock, cumulative and undeclared dividends in arrears	$ 470,000