Impairment Losses (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2011 Project Property	Dec. 31, 2011 Project
Impairment Losses (Textual) [Abstract]
No. of operating properties	2
No. of residential project	12
No. of residential development projects and related residential land sold		18
Sales price of residential land projects		$ 23.5
Total fair value of real estate assets, including investments in joint ventures	$ 104.5	$ 104.5