CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - Unaudited (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Distributions In Excess Of Earnings	Noncontrolling Interest in Joint Ventures
BALANCE at Dec. 31, 2011	$ 405,609	$ 3	$ 619,386	$ (216,560)	$ 2,780
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	13,605	0	0	13,375	230
Common dividends declared - $1.04 per share	(29,738)	0	0	(29,738)	0
Stock-based compensation, net of forfeitures	2,700	0	2,700	0	0
Issuance of 1,413,023 shares of common stock, common stock offering, net of expenses	69,807	0	69,807	0	0
Issuance of 4,500 shares of common stock, options exercised	108	0	108	0	0
Issuance of 2,012 shares of common stock, dividend reinvestment plan	104	0	104	0	0
Withheld 17,927 shares of common stock to satisfy tax withholding obligations in connection with the vesting of restricted stock	(812)	0	(812)	0	0
Distributions to noncontrolling interest	(220)	0	0	0	(220)
BALANCE at Jun. 30, 2012	$ 461,163	$ 3	$ 691,293	$ (232,923)	$ 2,790