CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
CONSOLIDATED BALANCE SHEETS
Properties held-for-sale, accumulated depreciation and amortization (in dollars)	$ 0	$ 4,100
Mortgage loans receivable, allowance for doubtful accounts (in dollars)	1,671	782
Straight-line rent receivable, allowance for doubtful accounts (in dollars)	1,541	1,513
Straight-line rent receivable and other assets related to properties held-for-sale, net of allowance for doubtful accounts (in dollars)	0	44
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	15,000	15,000
Preferred stock, shares issued	2,000	2,000
Preferred stock, shares outstanding	2,000	2,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	60,000	60,000
Common stock, shares issued	34,746	30,544
Common stock, shares outstanding	34,746	30,544
Straight-line rent receivable from a lessee that qualifies as a related party (in dollars)	$ 3,213	$ 3,191