CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Shares of Beneficial Interest, $1.00 Par	Capital Contributed in Excess of Par	Accumulated Other Comprehensive Income (Loss)	Distributions in Excess of Net Income	Non- controlling interest	Series A Preferred Stock	Series A Preferred Stock Preferred Shares $.01 par	Series A Preferred Stock Distributions in Excess of Net Income	Series B Preferred Stock	Series B Preferred Stock Preferred Shares $.01 par	Series B Preferred Stock Distributions in Excess of Net Income	Series C Preferred Stock	Series C Preferred Stock Preferred Shares $.01 par	Series C Preferred Stock Distributions in Excess of Net Income	Series D Preferred Stock	Series D Preferred Stock Preferred Shares $.01 par	Series D Preferred Stock Distributions in Excess of Net Income
Beginning balance at Dec. 31, 2016	$ 702,406	$ 69,553	$ 1,481,787	$ 1,622	$ (993,359)	$ 142,722		$ 46			$ 35
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(32,848)				(25,953)	(6,895)
Other comprehensive income	6,274			5,604		670
Preferred shares issued in Series C and D preferred share offerings, net	286,848		286,729											$ 69			$ 50
Preferred Shares redeemed	(115,000)		(110,851)		(4,103)			$ (46)
Amortization of deferred compensation	5,709		5,709
Shares issued upon redemption of Operating Partnership Units		39	375			(414)
Shares issued under employee compensation plan, net of shares retired	608	391	217
Dividends paid to preferred shareholders							$ (7,827)		$ (7,827)	$ (6,361)		$ (6,361)	$ (10,971)		$ (10,971)	$ (2,244)		$ (2,244)
Dividends paid to common shareholders ($0.84 per share)	(58,651)				(58,651)
Noncontrolling interests:
Distributions paid to Operating Partnership unit holders ($0.84 per unit)	(6,970)					(6,970)
Other contributions from noncontrolling interest, net	18					18
Ending Balance at Dec. 31, 2017	760,991	69,983	1,663,966	7,226	(1,109,469)	129,131					35			69			50
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(126,503)				(110,329)	(16,174)
Other comprehensive income	(2,034)			(1,818)		(216)
Amortization of deferred compensation	6,925		6,925
Shares issued under employee compensation plan, net of shares retired	663	512	151
Dividends paid to preferred shareholders										(6,361)		(6,361)	(12,420)		(12,420)	(8,594)		(8,594)
Dividends paid to common shareholders ($0.84 per share)	(59,145)				(59,145)
Noncontrolling interests:
Distributions paid to Operating Partnership unit holders ($0.84 per unit)	(6,949)					(6,949)
Other contributions from noncontrolling interest, net	(22)					(22)
Ending Balance at Dec. 31, 2018	546,551	70,495	1,671,042	5,408	(1,306,318)	105,770					35			69			50
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(13,000)				(10,872)	(2,128)
Other comprehensive income	(18,852)			(17,964)		(888)
Amortization of deferred compensation	6,212		6,212
Shares issued upon redemption of Operating Partnership Units		6,250	89,736			(95,986)
Shares issued under employee compensation plan, net of shares retired	698	805	(107)
Dividends paid to preferred shareholders										$ (6,364)		$ (6,364)	$ (12,419)		$ (12,419)	$ (8,592)		$ (8,592)
Dividends paid to common shareholders ($0.84 per share)	(63,787)				(63,787)
Noncontrolling interests:
Distributions paid to Operating Partnership unit holders ($0.84 per unit)	(3,004)					(3,004)
Other contributions from noncontrolling interest, net	(18)					(18)
Ending Balance at Dec. 31, 2019	$ 427,425	$ 77,550	$ 1,766,883	$ (12,556)	$ (1,408,352)	$ 3,746					$ 35			$ 69			$ 50