Condensed Consolidated Statements of Equity (USD $) In Thousands, unless otherwise specified	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Treasury Stock	Distributions in Excess of Net Income	Stockholders' Investment	Nonredeemable Noncontrolling Interests
Beginning Balance at Dec. 31, 2010	$ 792,851	$ 169,602	$ 106,962	$ 684,551	$ (86,840)	$ (114,196)	$ 760,079	$ 32,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(4,010)					(4,630)	(4,630)	620
Common stock issued pursuant to:
Restricted stock grants, net of amounts withheld for income taxes	(17)		243	(260)			(17)
Amortization of stock options and restricted stock, net of forfeitures	679		(4)	683			679
Change in fair value of redeemable noncontrolling interests	54			54			54
Distributions to noncontrolling interests	(590)							(590)
Cash preferred dividends paid	(3,227)					(3,227)	(3,227)
Cash common dividends paid	(4,653)					(4,653)	(4,653)
Ending Balance at Mar. 31, 2011	781,087	169,602	107,201	685,028	(86,840)	(126,706)	748,285	32,802
Beginning Balance at Dec. 31, 2011	637,395	169,602	107,272	687,835	(86,840)	(274,177)	603,692	33,703
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(9,314)					(9,885)	(9,885)	571
Common stock issued pursuant to:
Restricted stock grants, net of amounts withheld for income taxes	(171)		441	(612)			(171)
Amortization of stock options and restricted stock, net of forfeitures	583		(3)	586			583
Change in fair value of redeemable noncontrolling interests	0
Distributions to noncontrolling interests	(528)							(528)
Cash preferred dividends paid	(3,227)					(3,227)	(3,227)
Cash common dividends paid	(4,687)					(4,687)	(4,687)
Ending Balance at Mar. 31, 2012	$ 620,051	$ 169,602	$ 107,710	$ 687,809	$ (86,840)	$ (291,976)	$ 586,305	$ 33,746