CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Distributions in Excess of Net Income [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2014	$ 419,943	$ 25	$ 633	$ 815,961	$ (15,068)	$ (483,188)	$ 101,580
Balance (in shares) at Dec. 31, 2014		39,617,000	63,324,409
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock pursuant to Continuing Offer (Notes 9 and 10)	0		$ 1	(1)
Issuance of stock pursuant to Continuing Offer (Notes 9 and 10), shares		(72,061)	72,065
Repurchase of common stock (Note 6)	(84,982)		$ (12)	(84,970)
Repurchase of common stock (Note 6), Shares			(1,153,230)
Share-based compensation under employee and director benefit plans (Note 9)	2,809		$ 1	2,808
Share-based compensation under employee and director benefit plans (Note 9), shares			63,780
Adjustments of noncontrolling interests (Note 7)	0			23,324	(55)		(23,269)
Dividends and distributions	(57,889)					(41,460)
Distributions to noncontrolling interests							$ (16,429)
Other	(96)			3		(99)
Other, Shares
Net income	51,000					35,898	$ 15,102
Unrealized loss on interest rate instruments and other	(9,389)				(6,698)		(2,691)
Cumulative translation adjustment	(1,917)				(1,367)		(550)
Reclassification adjustment for amounts recognized in net income	2,893				2,064		829
Balance at Mar. 31, 2015	322,372	$ 25	$ 623	757,125	(21,124)	(488,849)	74,572
Balance (in shares) at Mar. 31, 2015		39,544,939	62,307,024
Balance at Dec. 31, 2015	120,811	$ 25	$ 602	652,146	(27,220)	(512,746)	8,004
Balance (in shares) at Dec. 31, 2015		39,544,939	60,233,561
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation under employee and director benefit plans (Note 9)	3,994		$ 1	3,993
Share-based compensation under employee and director benefit plans (Note 9), shares			109,353
Temporary Equity, Accretion to Redemption Value	(13,041)			(13,041)
Adjustments of noncontrolling interests (Note 7)	0			3,865	1		(3,866)
Dividends and distributions	(57,602)					(42,214)
Distributions to noncontrolling interests							(15,388)
Other	(188)			1		(189)
Net income	44,329					30,909	13,420
Unrealized loss on interest rate instruments and other	(11,860)				(8,380)		(3,480)
Cumulative translation adjustment	5,942				4,198		1,744
Reclassification adjustment for amounts recognized in net income	3,037				2,146		891
Balance at Mar. 31, 2016	$ 95,422	$ 25	$ 603	$ 646,964	$ (29,255)	$ (524,240)	$ 1,325
Balance (in shares) at Mar. 31, 2016		39,544,939	60,342,914