Summary of Preferred Stock Terms (Detail) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Preferred stock, Liquidation value	$ 2,871,000
Series A Convertible Preferred Stock
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%
Preferred stock, conversion Period	Any time
Series B Convertible Preferred Stock
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	426,000
Series C Convertible Preferred Stock
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	123,000
Series D Convertible Preferred Stock
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	1,867,000
Series E Convertible Preferred Stock
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	$ 449,000