PRO FORMA FINANCIAL INFORMATION (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 01, 2011	Jun. 30, 2012 Series of Individually Immaterial Business Acquisitions [Member]	Jun. 30, 2011 Series of Individually Immaterial Business Acquisitions [Member]	Jun. 30, 2012 Series of Individually Immaterial Business Acquisitions [Member] Facilities	Jun. 30, 2011 Series of Individually Immaterial Business Acquisitions [Member]	Dec. 31, 2011 Series of Individually Immaterial Business Acquisitions [Member] Facilities
Business Acquisition [Line Items]
Business Acquisition, Number of Acquired Properties				6		11
Stock issuance, Shares	11,700,000
Business Acquisition, Pro Forma Information [Abstract]
Revenues		$ 25,847	$ 25,550	$ 51,704	$ 50,963
Depreciation and amortization		7,662	7,889	15,335	15,813
Net income		$ 6,653	$ 6,853	$ 12,840	$ 13,502
Net income per common share, basic (USD per share)		$ 0.18	$ 0.19	$ 0.35	$ 0.37
Net income per common share, diluted (USD per share)		$ 0.18	$ 0.19	$ 0.35	$ 0.37
Weighted-average number of common shares outstanding, basic (in shares)		37,147,942	36,884,284	37,092,683	36,870,784
Weighted-average number of common shares outstanding, diluted (in shares)		37,191,687	36,956,179	37,119,005	36,940,575