Beneficiaries Equity of the Parent Company (Textual) (Details) - USD ($)		12 Months Ended
	Dec. 06, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 22, 2015
Class of Stock [Line Items]
Dividends, Common Stock	$ 28,100,000
Preferred Stock, Dividend Rate, Percentage		6.90%	6.90%
Dividends, Preferred Stock		$ 6,900,000	$ 6,900,000	$ 6,900,000
Authorized Amount					$ 100,000,000
Number of shares available for repurchase under the preexisting share repurchase program					539,200
Repurchased and Retired, Shares		0	5,209,437
Share Price			$ 12.90
Repurchased and Retired, Value			$ 67,325,000
Common stock price per share		$ 0.01	$ 0.01
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage		6.90%
Preferred Stock, Liquidation Preference Per Share		$ 25.00
Dividends, Preferred Stock	$ 1,700,000
Dividend Declared [Member]
Class of Stock [Line Items]
Dividends Payable, Amount Per Share	$ 0.16
Redeemable Common Limited Partnership Units
Class of Stock [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share		1,479,799	1,535,102	1,535,102