Service Providers And Related Party Agreements (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transaction [Line Items]
Management Fees	$ 2,838,239	$ 3,745,943	$ 2,194,672
Management Fees payable	234,540	329,420
Brokerage fees	54,290	89,069	90,048
Brokerage fees payable	$ 406	$ 7,102