Consolidated Statements Of Equity - USD ($) $ in Thousands	Common Shares [Member] Class A Common Shares [Member]	Common Shares [Member] Class B Common Shares [Member]	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 And LTIP Units [Member]	Noncontrolling Interests Consolidated Variable Interest Entity [Member]	Total Noncontrolling Interests [Member]	Total
Balance at Dec. 31, 2014	$ 497			$ 76	$ 1,194,547	$ (358)	$ (365,381)	$ 829,381	$ 29,082	$ (1,075)	$ 28,007	$ 857,388
Balance (in shares) at Dec. 31, 2014			49,708,771	7,600,000					2,199,434
Repurchase of Common Shares	(20)				(40,847)		(9,500)	(50,367)				(50,367)
Dividends and Distributions declared:
Common Shares							(27,159)	(27,159)				(27,159)
Preferred Shares							(7,178)	(7,178)				(7,178)
Common Units									$ (959)		(959)	(959)
LTIP Units									$ (345)		(345)	(345)
Dividend Reinvestment Plan					32			32				32
Dividend Reinvestment Plan (in shares)			477
Stock Based Compensation:
Grants					459			459				459
Grants (in shares)			24,802						128,842
Amortization					651			651	$ 3,022		3,022	3,673
Change in Fair Value of Derivative Instruments						(621)		(621)				(621)
Net Income (loss)							15,275	15,275	305	(343)	(38)	15,237
Balance at Jun. 30, 2015	477			$ 76	1,154,842	(979)	(393,943)	760,473	$ 31,105	(1,418)	29,687	790,160
Balance (in shares) at Jun. 30, 2015			47,769,899	7,600,000					2,328,276
Repurchase of Common Shares (in shares)			(1,964,151)
Balance at Dec. 31, 2015	444			$ 76	1,086,259	(466)	(408,274)	678,039	$ 31,876	(1,760)	30,116	708,155
Balance (in shares) at Dec. 31, 2015			44,457,368	7,600,000					2,319,301
Repurchase of Common Shares	(20)				(39,105)		(2)	(39,127)				(39,127)
Preferred Stock Issuance
Preferred Shares Offering, Net of Costs				$ 77	185,933			186,010				186,010
Preferred Shares Offering, Net of Costs (in shares)				7,700,000
Preferred Stock Redemption				$ (46)	(114,954)			(115,000)				(115,000)
Preferred Stock Redemption (in shares)				(4,600,000)
Dividends and Distributions declared:
Common Shares							(24,357)	(24,357)				(24,357)
Preferred Shares							(7,589)	(7,589)				(7,589)
Common Units									$ (954)		(954)	(954)
LTIP Units									(882)		(882)	(882)
Dividend Reinvestment Plan					31			31				31
Dividend Reinvestment Plan (in shares)			1,659
Stock Based Compensation:
Grants					(613)			(613)	$ 1,060		1,060	447
Grants (in shares)			39,345						294,245
Amortization					639			639	$ 4,192		4,192	4,831
Change in Fair Value of Derivative Instruments						(221)		(221)				(221)
Net Income (loss)							102,479	102,479	4,391	(330)	4,061	106,540
Balance at Jun. 30, 2016	$ 424			$ 107	$ 1,118,190	$ (687)	$ (337,743)	$ 780,291	$ 39,683	$ (2,090)	$ 37,593	$ 817,884
Balance (in shares) at Jun. 30, 2016			42,426,365	10,700,000					2,613,546
Repurchase of Common Shares (in shares)			(2,072,007)