Consolidated Statements Of Equity (USD $) In Thousands, except Share data, unless otherwise specified	Common Shares [Member] Class A Common Shares [Member] USD ($)	Common Shares [Member]	Preferred Shares [Member] USD ($)	Additional Paid-In Capital [Member] USD ($)	Accumulated Other Comprehensive Loss [Member] USD ($)	Distributions in Excess of Net Earnings [Member] USD ($)	Total Shareholders' Equity [Member] USD ($)	Noncontrolling Interests Common Units [Member] USD ($)	Noncontrolling Interests Consolidated Joint Ventures [Member] USD ($)	Noncontrolling Interests Consolidated Variable Interest Entity [Member] USD ($)	Noncontrolling Interests [Member] USD ($)	Redeemable Noncontrolling Interests Shares [Member] USD ($)	Total USD ($)
Balance at Dec. 31, 2012	$ 1,986		$ 70	$ 1,178,292	$ (1,786)	$ (348,734)	$ 829,828	$ 15,484	$ 476	$ 15,960	$ 845,788	$ 15,321
Balance (in shares) at Dec. 31, 2012		198,672,356	7,000,000					4,048,254				3,064,252
Unit Conversion/Redemption	1			(234)			(233)	(767)		(767)	(1,000)
Unit Conversion/Redemption (in shares)		27,790						(197,790)
Reallocation of Noncontrolling Interest								15,321		15,321	15,321	(15,321)
Reallocation of Noncontrolling Interest (in shares)								3,064,252				(3,064,252)
Preferred Stock
Preferred Shares Offering, net of costs			30	72,340			72,370				72,370
Preferred Shares Offering, net of costs (in shares)			3,000,000
Preferred Shares Redemption			(24)	(59,976)			(60,000)				(60,000)
Preferred Shares Redemption (in shares)			(2,400,000)
Dividends and Distributions declared:
Common Shares						(37,572)	(37,572)				(37,572)
Preferred Shares						(11,022)	(11,022)				(11,022)
Common Units								(1,254)		(1,254)	(1,254)
Dividend Reinvestment Plan				27			27				27		27
Dividend Reinvestment Plan (in shares)		5,122
Share Based Compensation
Grants	40			285			325				325
Grants (in shares)		3,968,534
Amortization				8,026			8,026				8,026
Change in Fair Value of Derivative Instruments					1,364		1,364				1,364
Net Income						13,337	13,337	2	(630)	(628)	12,709
Balance at Sep. 30, 2013	2,027		76	1,198,760	(422)	(383,991)	816,450	28,786	(154)	28,632	845,082
Balance (in shares) at Sep. 30, 2013		202,673,802	7,600,000					6,914,716
Balance at Dec. 31, 2013	2,028		76	1,200,798	(376)	(364,568)	837,958	29,523	(342)	29,181	867,139		867,139
Balance (in shares) at Dec. 31, 2013		202,759,419	7,600,000					6,914,716
Repurchase of Common Shares	(26)			(13,637)		(1,621)	(15,284)				(15,284)		(15,284)
Repurchase of Common Shares (in shares)		(2,626,854)											(2,626,854)
Dividends and Distributions declared:
Common Shares						(38,171)	(38,171)				(38,171)
Preferred Shares						(10,767)	(10,767)				(10,767)
Common Units								(1,309)		(1,309)	(1,309)
Dividend Reinvestment Plan				34			34				34		34
Dividend Reinvestment Plan (in shares)		6,123
Share Based Compensation
Grants	6			403			409				409
Grants (in shares)		591,243
Amortization				4,326			4,326				4,326
Change in Fair Value of Derivative Instruments					286		286				286
Net Income						58,560	58,560	1,657	(557)	1,100	59,660
Balance at Sep. 30, 2014	$ 2,008		$ 76	$ 1,191,924	$ (90)	$ (356,567)	$ 837,351	$ 29,871	$ (899)	$ 28,972	$ 866,323		$ 866,323
Balance (in shares) at Sep. 30, 2014		200,729,931	7,600,000					6,914,716