CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $) In Thousands	Total	Series A Cumulative Redeemable Preferred Stock [Member]	Common Stock [Member]	Additional Common and Preferred Paid-in Capital [Member]	Accumulated Deficit and Distributions [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Stockholder's Equity [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2011	$ 229,995	$ 0	$ 307	$ 248,599	$ (22,550)	$ (387)	$ 225,969	$ 4,026
Net proceeds of sale of preferred stock	54,893	23	0	54,870	0	0	54,893	0
Net proceeds of sale of common stock	72,162	0	75	72,087	0	0	72,162	0
Issuance of restricted stock	0	0	4	(4)	0	0	0	0
Amortization of restricted stock awards and operating partnership units	2,252	0	0	1,628	0	0	1,628	624
Dividends on preferred stock	(4,114)	0	0	0	(4,114)	0	(4,114)	0
Dividends on common stock	(22,275)	0	0	0	(22,275)	0	(22,275)	0
Dividends to noncontrolling interests	(281)	0	0	0	0	0	0	(281)
Change in fair value of interest rate derivatives	332	0	0	0	0	329	329	3
Foreign currency translation	0
Net (loss) income	10,418	0	0	0	10,372	0	10,372	46
Balance at Dec. 31, 2012	343,382	23	386	377,180	(38,567)	(58)	338,964	4,418
Net proceeds of sale of preferred stock	91,282	38	0	91,244	0	0	91,282	0
Net proceeds of sale of common stock	299,719	0	255	299,464	0	0	299,719	0
Equity portion of issuance of convertible notes	3,207	0	0	3,207	0	0	3,207	0
Issuance of restricted stock	0	0	4	(4)	0	0	0	0
Amortization of restricted stock awards and operating partnership units	3,300	0	0	2,805	0	0	2,805	495
Dividends on preferred stock	(6,183)	0	0	0	(6,183)	0	(6,183)	0
Dividends on common stock	(42,565)	0	0	0	(42,565)	0	(42,565)	0
Dividends to noncontrolling interests	(287)	0	0	0	0	0	0	(287)
Change in fair value of interest rate derivatives	59	0	0	0	0	58	58	1
Foreign currency translation	(71)	0	0	0	0	(71)	(71)	0
Net (loss) income	1,238	0	0	0	1,272	0	1,272	(34)
Balance at Dec. 31, 2013	693,081	61	645	773,896	(86,043)	(71)	688,488	4,593
Issuance of restricted stock	0	0	3	(3)	0	0	0	0
Amortization of restricted stock awards and operating partnership units	5,744	0	0	5,744	0	0	5,744	0
Dividends on preferred stock	(12,200)	0	0	0	(12,200)	0	(12,200)	0
Dividends on common stock	(37,852)	0	0	0	(37,852)	0	(37,852)	0
Dividends to noncontrolling interests	(250)	0	0	0	0	0	0	(250)
Change in fair value of interest rate derivatives	0
Foreign currency translation	(2,564)	0	0	0	0	(2,545)	(2,545)	(19)
Non-controlling interest in Copper Beech at Ames	0	0	0	(5,639)	0	0	(5,639)	5,639
Net (loss) income	(163,956)	0	0	0	(162,723)	0	(162,723)	(1,233)
Balance at Dec. 31, 2014	$ 482,003	$ 61	$ 648	$ 773,998	$ (298,818)	$ (2,616)	$ 473,273	$ 8,730