CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - Unaudited (USD $)	Total	Common Stock	Additional Paid-in Capital	Distributions In Excess Of Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interest in Joint Ventures
BALANCE at Dec. 31, 2013	$ 518,705,000	$ 3,000	$ 790,535,000	$ (278,169,000)	$ 1,629,000	$ 4,707,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,514,000	0	0	8,372,000	0	142,000
Net unrealized change in fair value of interest rate swaps	(1,037,000)	0	0	0	(1,037,000)	0
Common dividends declared - $.54 per share	(17,054,000)	0	0	(17,054,000)	0	0
Stock-based compensation, net of forfeitures	2,069,000	0	2,069,000	0	0	0
Issuance of 321,645 shares of common stock, common stock offering, net of expenses	19,602,000	0	19,602,000	0	0	0
Issuance of 833 shares of common stock, dividend reinvestment plan	52,000	0	52,000	0	0	0
Withheld 31,417 shares of common stock to satisfy tax withholding obligations in connection with the vesting of restricted stock	(1,844,000)	0	(1,844,000)	0	0	0
Distributions to noncontrolling interest	(189,000)	0	0	0	0	(189,000)
BALANCE at Mar. 31, 2014	$ 528,818,000	$ 3,000	$ 810,414,000	$ (286,851,000)	$ 592,000	$ 4,660,000