REAL ESTATE PROPERTIES HELD FOR INVESTMENT - Narrative (Details) $ in Thousands			3 Months Ended	9 Months Ended
	Oct. 01, 2017 Property	Sep. 30, 2017 USD ($) Property acquisition Facilitiy	Sep. 30, 2017 USD ($) Property acquisition Facilitiy	Sep. 30, 2017 USD ($) Property acquisition Facilitiy	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Real Estate Properties [Line Items]
Payment of contingent consideration				$ 0
Facilities transitioned to managed property structure with earn out terminated | Property				8
Change in fair value of contingent consideration				$ 552	$ (50)
Weighted average lease expiration period				9 years
Security deposit liability		$ 35,600	$ 35,600	$ 35,600		$ 2,700
Reserve for unpaid cash rents		3,500	3,500	3,500		3,200
Allowance for straight-line rental income		$ 2,800	$ 2,800	$ 2,800		$ 3,700
Genesis [Member]
Real Estate Properties [Line Items]
Memoranda of understanding facilities | Facilitiy				35
Number of leased facilities | Facilitiy		43	43	43
Minimum [Member]
Real Estate Properties [Line Items]
Lease expiration period				1 year
Maximum [Member]
Real Estate Properties [Line Items]
Lease expiration period				15 years
Acquisitions With Contingent Consideration Arrangements [Member]
Real Estate Properties [Line Items]
Number of Properties | acquisition		3	3	3
Estimated earn-out value		$ 3,200	$ 3,200	$ 3,200
Acquisitions With Contingent Consideration Arrangements [Member] | Accounts Payable and Accrued Liabilities [Member]
Real Estate Properties [Line Items]
Contingent consideration liability		$ 300	300	300
Acquisitions With Contingent Consideration Arrangements [Member] | Other Operating Income (Expense) [Member]
Real Estate Properties [Line Items]
Change in fair value of contingent consideration			$ 300	$ (600)
Non Triple-net Operating Leases [Member]
Real Estate Properties [Line Items]
Number of Properties | Property		11	11	11
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Genesis [Member]
Real Estate Properties [Line Items]
Number of facilities sold | Property		2
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Subsequent Event [Member] | Genesis [Member]
Real Estate Properties [Line Items]
Number of facilities sold | Property	2
Held-for-sale [Member] | Subsequent Event [Member] | Genesis [Member]
Real Estate Properties [Line Items]
Number of facilities sold | Property	20