Consolidated Statement of Changes in Equity (USD $) In Thousands, except Share data	Total	Parent [Member]	Common Class A [Member]	Common Class B [Member]	Additional Paid-in Capital [Member]	Accumulated Distributions in Excess of Net Income [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2010	$ 84,283	$ 62,708	$ 3	$ 2	$ 93,357	$ (30,654)	$ 0	$ 21,575
Beginning Balance (in units), at Dec. 31, 2010								1,815,000
Beginning Balance (in shares), at Dec. 31, 2010			3,471,187	2,200,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of commons shares (shares)			0	5,310,000
Issuance of common shares (value)	59,683	59,683	0	5	59,678
Dividend reinvestment plan				1,269
Dividend reinvestment plan	(16)	(16)			(16)
Share-based compensation (shares)			(97)
Share-based compensation (value)	86	86			86
Dividends and distributions	(9,785)	(8,320)				(8,320)		(1,465)
Unrealized loss on change in fair value of available-for-sale marketable securities	(1,881)	(1,545)					(1,545)	(336)
Net income	683	561				561		122
Ending Balance at Sep. 30, 2011	$ 133,053	$ 113,157	$ 3	$ 7	$ 153,105	$ (38,413)	$ (1,545)	$ 19,896
Ending Balance (in units), at Sep. 30, 2011								1,815,000
Ending Balance (in shares), at Sep. 30, 2011			3,471,090	7,511,269