Consolidated Balance Sheets Parenthetical (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Current Assets:
Investments in joint ventures at fair value	$ 45,127,000	$ 34,654,000
Equity:
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	46,089,646	41,291,596
Common stock, shares outstanding	44,974,706	40,179,906
Treasury stock, par value at cost	$ 0.0001	$ 0.0001
Treasury stock, shares	1,114,940	1,111,690
Cumulative preferred stock subject to mandatory redemption Series A [Member]
Equity:
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred Stock, liquidation preference per share	$ 1,000	$ 1,000
Preferred stock, dividend rate, percentage	6.00%	6.00%
Preferred stock, shares issued	100,000	100,000
Mandatory redemption date	May 19, 2015
Cumulative preferred stock subject to mandatory redemption Series B [Member]
Equity:
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred Stock, liquidation preference per share	$ 1,000	$ 1,000
Preferred stock, dividend rate, percentage	6.46%	6.46%
Preferred stock, shares issued	32,550	32,550
Mandatory redemption date	Nov. 03, 2018
Cumulative Preferred Stock Subject to Mandatory Redemption [Member]
Equity:
Preferred stock, shares authorized	1,000,000	1,000,000