CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
CONDENSED CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts (in dollars)	$ 320	$ 625
Accumulated amortization, lease intangibles (in dollars)	20,026	33,050
Accumulated amortization, acquired below-market lease contracts (in dollars)	5,702	10,062
Series A Cumulative Preferred Stock, dividend rate (as a percent)	7.25%	7.25%
Series A Cumulative Preferred Stock, liquidation preference	$ 115,000	$ 115,000
Series A Cumulative Preferred Stock, liquidation preference (in dollars per share)	$ 25.00	$ 25.00
Series A Cumulative Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A Cumulative Preferred Stock, shares issued	4,600,000	4,600,000
Series A Cumulative Preferred Stock, shares outstanding	4,600,000	4,600,000
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	100,000,000	100,000,000
Common Stock, shares issued	21,412,432	21,202,673
Common Stock, shares outstanding	21,412,432	21,202,673