Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Operating, consolidated variable interest entities	$ 265,138	$ 264,506
Accumulated depreciation and amortization, consolidated variable interest entities	19,086	12,024
Debt issuance costs, accumulated amortization	9,535	10,140
Mortgages payable, consolidated variable interest entities	$ 202,782	$ 205,299
Preferred shares, authorized	15,000,000	15,000,000
Preferred shares, par	$ 0.01	$ 0.01
Preferred Shares, 5.417% Series 1 Cumulative Convertible liquidation preference	$ 25	$ 25
Preferred shares, shares issued	399,896	399,896
Preferred shares, shares outstanding	399,896	399,896
Common shares of beneficial interest, par	$ 0.01	$ 0.01
Common shares of beneficial interest, shares authorized	100,000,000	100,000,000
Common shares of beneficial interest, shares issued	66,701,422	64,815,446
Common Stock, Shares, Outstanding	66,701,422	64,815,446
5.417% Series 1 Cumulative Convertible Preferred [Member]
Preferred Shares, percentage	5.417%	5.417%