SUMMARIZED CONDENSED CONSOLIDATING INFORMATION (Condensed Consolidating Statement of Income) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues:
Rental income	$ 31,518,000	$ 24,820,000	$ 62,993,000	$ 48,483,000
Interest and other income	757,000	297,000	1,304,000	361,000
Total revenues	32,275,000	25,117,000	64,297,000	48,844,000
Expenses:
Depreciation and amortization	8,222,000	7,557,000	16,468,000	14,860,000
Interest	10,143,000	7,898,000	20,145,000	15,596,000
General and administrative	3,422,000	3,489,000	8,139,000	7,810,000
Total expenses	21,787,000	18,944,000	44,752,000	38,266,000
Loss on extinguishment of debt	(9,750,000)	(250,000)	(9,750,000)	(250,000)
Other income	(1,400,000)		(900,000)
Total other income (expense)	(11,150,000)	(250,000)	(10,650,000)	(250,000)
(Income) loss in subsidiary	0	0	0	0
Net income	(662,000)	5,923,000	8,895,000	10,328,000
Preferred dividends	(2,523,000)		(2,827,000)
Net income attributable to common stockholders	(3,185,000)	5,923,000	6,068,000	10,328,000
Net income per common share, basic (USD per shares)	$ (0.09)	$ 0.16	$ 0.16	$ 0.28
Net income per common share, diluted (USD per shares)	$ (0.09)	$ 0.16	$ 0.16	$ 0.28
Weighted-average number of common shares outstanding, basic (in shares)	37,357,112	37,147,942	37,321,813	37,092,683
Weighted-average number of common shares outstanding, diluted (in shares)	37,357,112	37,191,687	37,789,804	37,119,005
Parent Company [Member]
Revenues:
Rental income	0	0	0	0
Interest and other income	16,000	1,000	69,000	7,000
Total revenues	16,000	1,000	69,000	7,000
Expenses:
Depreciation and amortization	13,000	12,000	25,000	24,000
Interest	0	0	0	0
General and administrative	3,091,000	3,083,000	7,675,000	6,920,000
Total expenses	3,104,000	3,095,000	7,700,000	6,944,000
Loss on extinguishment of debt	0	0	0	0
Other income	0		0
Total other income (expense)	0	0	0	0
(Income) loss in subsidiary	2,426,000	9,017,000	16,526,000	17,265,000
Net income	(662,000)	5,923,000	8,895,000
Preferred dividends	(2,523,000)		(2,827,000)
Net income attributable to common stockholders	(3,185,000)		6,068,000	10,328,000
Issuers [Member]
Revenues:
Rental income	0	0	0	0
Interest and other income	0	0	0	0
Total revenues	0	0	0	0
Expenses:
Depreciation and amortization	0	0	0	0
Interest	7,722,000	4,757,000	14,438,000	9,514,000
General and administrative	2,000	1,000	4,000	2,000
Total expenses	7,724,000	4,758,000	14,442,000	9,516,000
Loss on extinguishment of debt	(9,750,000)	0	(9,750,000)	0
Other income	0		0
Total other income (expense)	(9,750,000)	0	(9,750,000)	0
(Income) loss in subsidiary	19,900,000	13,775,000	40,718,000	26,781,000
Net income	2,426,000	9,017,000	16,526,000
Preferred dividends	0		0
Net income attributable to common stockholders	2,426,000		16,526,000	17,265,000
Combined Guarantor Subsidiaries [Member]
Revenues:
Rental income	24,219,000	18,372,000	48,353,000	35,586,000
Interest and other income	741,000	296,000	1,235,000	354,000
Total revenues	24,960,000	18,668,000	49,588,000	35,940,000
Expenses:
Depreciation and amortization	6,302,000	5,492,000	12,617,000	10,724,000
Interest	639,000	715,000	1,979,000	1,178,000
General and administrative	299,000	376,000	412,000	839,000
Total expenses	7,240,000	6,583,000	15,008,000	12,741,000
Loss on extinguishment of debt	0	0	0	0
Other income	(1,400,000)		(900,000)
Total other income (expense)	(1,400,000)	0	(900,000)	0
(Income) loss in subsidiary	930,000	(55,000)	1,909,000	147,000
Net income	17,250,000	12,030,000	35,589,000
Preferred dividends	0		0
Net income attributable to common stockholders	17,250,000		35,589,000	23,346,000
Combined Non-Guarantor Subsidiaries [Member]
Revenues:
Rental income	7,299,000	6,448,000	14,640,000	12,897,000
Interest and other income	0	0	0	0
Total revenues	7,299,000	6,448,000	14,640,000	12,897,000
Expenses:
Depreciation and amortization	1,907,000	2,053,000	3,826,000	4,112,000
Interest	1,782,000	2,426,000	3,728,000	4,904,000
General and administrative	30,000	29,000	48,000	49,000
Total expenses	3,719,000	4,508,000	7,602,000	9,065,000
Loss on extinguishment of debt	0	(250,000)	0	(250,000)
Other income	0		0
Total other income (expense)	0	(250,000)	0	(250,000)
(Income) loss in subsidiary	0	0	0	0
Net income	3,580,000	1,690,000	7,038,000
Preferred dividends	0		0
Net income attributable to common stockholders	3,580,000		7,038,000	3,582,000
Elimination [Member]
Revenues:
Rental income	0	0	0	0
Interest and other income	0	0	0	0
Total revenues	0	0	0	0
Expenses:
Depreciation and amortization	0	0	0	0
Interest	0	0	0	0
General and administrative	0	0	0	0
Total expenses	0	0	0	0
Loss on extinguishment of debt	0	0	0	0
Other income	0		0
Total other income (expense)	0	0	0	0
(Income) loss in subsidiary	(23,256,000)	(22,737,000)	(59,153,000)	(44,193,000)
Net income	(23,256,000)	(22,737,000)	(59,153,000)
Preferred dividends	0		0
Net income attributable to common stockholders	$ (23,256,000)		$ (59,153,000)	$ (44,193,000)