CCP MERGER AND RECENT REAL ESTATE ACQUISITIONS - Narrative (Details) $ in Thousands, shares in Millions							3 Months Ended		9 Months Ended
	Aug. 17, 2017 Property	Aug. 17, 2017 shares	Aug. 17, 2017 direct_financing_lease_property	Aug. 17, 2017 firm	Aug. 17, 2017 USD ($)	Aug. 17, 2017 Investment	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) Facilitiy	Sep. 30, 2016 USD ($) Facilitiy
Business Acquisition [Line Items]
Total revenues							$ 111,789	$ 61,927	$ 239,175	$ 198,735
Net income attributable to common stockholders							12,534	22,776	46,756	39,419
Merger and acquisition costs							23,299	1,051	29,750	1,222
Care Capital Properties [Member]
Business Acquisition [Line Items]
Exchange ratio	1.123	1.123	1.123	1.123	1.123	1.123
Shares issued in merger (in shares) | shares		94.0
Number of acquired properties | Property	330
Number of loan receivable investments acquired | Investment						18
Number of specialty valuation firms | firm				1
Estimated consideration transferred					$ 2,100,000
Total revenues							45,100		45,100
Net income attributable to common stockholders							30,600		30,600
Merger and acquisition costs							23,300		$ 29,700
Care Capital Properties [Member] | Lease intangible assets [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets and liabilities, weighted average amortization period as of date of acquisition									11 years
Care Capital Properties [Member] | Lease intangible liabilities [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets and liabilities, weighted average amortization period as of date of acquisition									10 years
Care Capital Properties [Member] | Skilled Nursing Transitional Care Facilities [Member]
Business Acquisition [Line Items]
Number of acquired properties	296		1
Care Capital Properties [Member] | Senior Housing Facilities [Member]
Business Acquisition [Line Items]
Number of acquired properties | Property	13
Care Capital Properties [Member] | Specialty Hospitals and Other [Member]
Business Acquisition [Line Items]
Number of acquired properties | Property	21
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Total revenues							1,500	1,700	$ 1,600	1,700
Net income attributable to common stockholders							$ 1,400	$ 100	$ 1,400	$ 100
Series of Individually Immaterial Business Acquisitions [Member] | Tenant origination and absorption costs [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets and liabilities, weighted average amortization period as of date of acquisition									13 years
Series of Individually Immaterial Business Acquisitions [Member] | Tenant relationship [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets and liabilities, weighted average amortization period as of date of acquisition									23 years
Series of Individually Immaterial Business Acquisitions [Member] | Skilled Nursing Transitional Care Facilities [Member]
Business Acquisition [Line Items]
Number of acquired properties | Facilitiy									21	1
Series of Individually Immaterial Business Acquisitions [Member] | Senior Housing Facilities [Member]
Business Acquisition [Line Items]
Number of acquired properties | Facilitiy									1	3