Beneficiaries Equity of The Parent Company (DetailsTextuals) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	12 Months Ended			0 Months Ended		0 Months Ended	12 Months Ended					12 Months Ended
	Apr. 10, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 10, 2013 Dividend Declared [Member]	Dec. 10, 2013 Dividend Paid	Jan. 15, 2014 Series E Preferred Stock [Member]	Dec. 31, 2013 Series E Preferred Stock [Member]	Dec. 31, 2013 Class A Units [Member]	Dec. 31, 2012 Class A Units [Member]	Dec. 31, 2011 Class A Units [Member]	Nov. 05, 2013 Offering Program [Member]	Dec. 31, 2012 6.90% Series E Preferred Stock [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Value			$ (103,448)										$ (43)
Net Proceeds from Issuance of Preferred Stock and Preference Stock		0	96,237	0
Stock Redeemed or Called During Period, Shares													(4,300,000)
Beneficiaries Equity of The Parent Company (Textuals) [Abstract]
Antidilutive securities excluded from computation of earnings per share									1,763,739	1,845,737	2,698,647
Distributions Declared, Per Share		$ 0.60	$ 0.60	$ 0.60	$ 0.15
Preferred Stock, Shares Issued		4,000,000	4,000,000
Shares authorized for Equity Offering Program												16,000,000
Issuance of Common Shares of Beneficial Interest, shares	12,650,000												4,000,000
Issuance of Common Shares of Beneficial Interest		182,034	96,850	8,272									40
Remaining shares available for sales												16,000,000
Additional shares Expected to be purchased under program		539,200
Dividends paid for preferred shares		6,900	10,405	7,992			1,700
Additional shares granted under option to purchase in public offering	1,650,000
Proceeds from Issuance of Common Stock	181,500	181,527	0	7,930
Percentage of Preferential return		6.90%						6.90%
Preferred Stock, Liquidation Preference Per Share								$ 25.00
Dividends Payable, Amount		25,584	23,652			23,900
Redemption Premium		$ 0	$ 4,052	$ 0