PRO FORMA FINANCIAL INFORMATION (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended		12 Months Ended		1 Months Ended	12 Months Ended
	Aug. 01, 2011	Aug. 02, 2011	Dec. 31, 2012 note	Dec. 31, 2011	Dec. 31, 2010 Series of Individually Immaterial Business Acquisitions [Member]	Dec. 31, 2012 Series of Individually Immaterial Business Acquisitions [Member] Facilities	Dec. 31, 2011 Series of Individually Immaterial Business Acquisitions [Member] Facilities	Dec. 31, 2012 United States Department of Housing and Urban Development [Member] note	Dec. 31, 2012 Refinance of Debt Q4 [Member] United States Department of Housing and Urban Development [Member] note	Jul. 26, 2012 Issuance of Debt Additional Senior Notes [Member]
Business Acquisition
Number of acquired properties						23	11
Business Acquisition, Number of Loans and Leases Receivable						3
Stock issuance, shares	11,700,000	11,700,000
Business Acquisition, Pro Forma Information [Abstract]
Revenues					$ 130,470	$ 127,043
Depreciation and amortization					35,370	34,226
Net income					43,765	37,631
Net income per common share, basic (USD per share)					$ 1.19	$ 1.02
Net income per common share, diluted (USD per share)					$ 1.18	$ 1.01
Weighted-average number of common shares outstanding, basic (in shares)					36,922,458	37,061,111
Weighted-average number of common shares outstanding, diluted (in shares)					36,984,266	37,321,517
Debt Instrument, Face Amount										100,000
Debt Instrument, Refinanced, Number of Instruments Refinanced								4	6
Debt Instrument, Paid Off, Number of Instruments Paid off			1
Secured revolving credit facility			$ 92,500	$ 0