QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
Revenues from continuing operations	$ 50,127	$ 47,640	$ 51,559	$ 48,398	$ 52,744	$ 55,384	$ 61,299	$ 66,949	$ 197,724	$ 236,376	$ 265,931
Gain on sale of real estate					23,005	74,715	116,283	187,734	0	401,737	39,666
Net income (loss) from continuing operations	(900)	(529)	1,949	622	22,060	72,391	91,372	193,935	1,142	379,758	30,712
Net income (loss)	(900)	(529)	1,949	622	22,060	72,391	91,372	193,935	1,142	379,758	34,565
Net income (loss) attributable to the Company	(906)	(528)	1,937	618	22,049	72,395	91,363	193,930	1,121	379,737	34,547
Redeemable preferred stock dividends declared and accumulated	(4,043)	(3,921)	(3,814)	(3,645)	(1,685)	(138)	(72)	(31)	(15,423)	(1,926)	(9)
Redeemable preferred stock redemptions	1	1	1	1	2	0	0	0	4	2	0
Net income (loss) available to common stockholders	$ (4,948)	$ (4,448)	$ (1,876)	$ (3,026)	$ 20,366	$ 72,257	$ 91,291	$ 193,899	$ (14,298)	$ 377,813	$ 34,538
BASIC AND DILUTED NET LOSS ATTRIBUTABLE TO COMMON STOCKHOLDERS PER SHARE (1):
Continuing operations (in usd per share)	$ (0.11)	$ (0.10)	$ (0.04)	$ (0.07)	$ 0.36	$ 1.25	$ 1.16	$ 2.31	$ (0.33)	$ 5.47	$ 0.34
Net income (in usd per share)	$ (0.11)	$ (0.10)	$ (0.04)	$ (0.07)	$ 0.36	$ 1.25	$ 1.16	$ 2.31	$ (0.33)	$ 5.47	$ 0.38
Weighted average shares of common stock outstanding - basic (in shares)	43,795	43,795	43,791	43,785	55,885	57,876	78,871	84,048	43,792	69,062	91,328
Weighted average shares of Common Stock outstanding - diluted (in shares)	43,795	43,795	43,791	43,785	55,917	57,876	78,871	84,048	43,792	69,070	91,328