Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Investments in real estate, variable interest entities	$ 65,029	$ 21,423
Restricted cash held in escrows, variable interest entities	6,637	1,101
Allowances on accounts receivable	478	374
Lease intangibles, variable interest entities	20,059	3,485
Mortgage loans payable, variable interest entities	65,836	23,184
Notes payable, variable interest entities	864	876
Below market lease intangibles, variable interest entities	$ 605	$ 51
Series D Cumulative Redeemable Preferred Shares, liquidation preference	$ 25	$ 25
Series D Cumulative Redeemable Preferred Shares, shares authorized	5,060,000	5,060,000
Series D Cumulative Redeemable Preferred Shares, shares issued	4,820,000	4,820,000
Series D Cumulative Redeemable Preferred Shares, shares outstanding	4,820,000	4,820,000
Common Shares, par value	$ 1	$ 1
Common Shares, shares issued	36,397,949	33,018,711
Common Shares, shares outstanding	36,397,949	33,018,711