Consolidated Statements Of Equity (USD $) In Thousands, except Share data, unless otherwise specified	Common Shares [Member] Class A Common Shares [Member]	Preferred Shares [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Distributions in Excess of Net Earnings [Member]	Total Shareholders' Equity [Member]	Noncontrolling Interests Common Units [Member]	Noncontrolling Interests Consolidated Joint Ventures [Member]	Noncontrolling Interests Consolidated Variable Interest Entity [Member]	Noncontrolling Interests [Member]	Redeemable Noncontrolling Interests Common Units [Member]	Total
Balance, redeemable noncontrolling interests at Dec. 31, 2011											$ 14,955
Balance at Dec. 31, 2011	1,699	70	1,041,027	(1,151)	(310,974)	730,671	16,864	307		17,171		747,842
Unit Conversion			52			52	(52)			(52)
Reclassification / Reallocation of Noncontrolling Interest			(1,548)			(1,548)					1,548	(1,548)
Dividends and Distributions declared:
Common Stock Offering, net of costs	240		128,457			128,697						128,697
Common Stock Offering, net of costs (in shares)	25,000		(25,000)
Common Stock ($0.12 per share)					(22,304)	(22,304)						(22,304)
Preferred Stock					(7,000)	(7,000)						(7,000)
Common Units ($0.12 per share)							(503)			(503)	(369)	(503)
Dividend Reinvestment Plan			8			8						8
Stock Based Compensation
Grants	20		2,454			2,474						2,474
Amortization			3,249			3,249						3,249
Consolidation of Variable Interest Entity									956	956		956
Deconsolidation of Consolidated Joint Ventures								(307)		(307)		(307)
Change in Fair Value of Derivative Instruments				(174)		(174)						(174)
Net Income (Loss)					9,420	9,420	57		(43)	14	41	9,434
Balance, redeemable noncontrolling interests at Jun. 30, 2012											16,175
Balance at Jun. 30, 2012	1,984	70	1,173,674	(1,325)	(330,858)	843,545	16,366		913	17,279		860,824
Balance, redeemable noncontrolling interests at Dec. 31, 2012											15,321	15,321
Balance at Dec. 31, 2012	1,986	70	1,178,292	(1,786)	(348,734)	829,828	15,484		476	15,960		845,788
Unit Conversion	1		(234)			(233)	(767)			(767)		(1,000)
Reclassification / Reallocation of Noncontrolling Interest							15,251			15,251	(15,251)	15,251
Preferred Stock
Preferred Stock Offering, net of costs		30	72,341			72,371						72,371
Preferred Stock Redemption		(24)	(59,976)			(60,000)						(60,000)
Dividends and Distributions declared:
Common Stock ($0.12 per share)					(25,414)	(25,414)						(25,414)
Preferred Stock					(7,433)	(7,433)						(7,433)
Common Units ($0.12 per share)							(838)			(838)		(838)
Dividend Reinvestment Plan			19			19						19
Stock Based Compensation
Grants	40		285			325						325
Amortization			6,187			6,187						6,187
Change in Fair Value of Derivative Instruments				2,363		2,363						2,363
Net Income (Loss)					10,872	10,872	37		(430)	(393)	(70)	10,479
Balance at Jun. 30, 2013	$ 2,027	$ 76	$ 1,196,914	$ 577	$ (370,709)	$ 828,885	$ 29,167		$ 46	$ 29,213		$ 858,098