Consolidated Balance Sheets (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets
Preferred stock, Series B cumulative perpetual convertible, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, Series B cumulative perpetual convertible, shares authorized	5,000,000	5,000,000
Preferred stock, Series B cumulative perpetual convertible, dividend rate (as a percent)	10.00%	10.00%
Preferred stock, Series B cumulative perpetual convertible, shares issued	57,500	57,500
Preferred stock, Series B cumulative perpetual convertible, shares outstanding	57,266	57,500
Preferred stock, Series B cumulative perpetual convertible, liquidation preference per share	$ 1,000	$ 1,000
Preferred stock, Series B cumulative perpetual convertible, liquidation preference total	$ 57,266,000	$ 57,500,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares outstanding	25,272,734	25,088,539