PRO FORMA FINANCIAL INFORMATION (UNAUDITED) - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) Property Facilitiy	Dec. 31, 2016 USD ($) Facilitiy	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Merger and acquisition costs	$ 30,255	$ 1,197	$ 7,023
Recent Real Estate Acquisitions
Business Acquisition [Line Items]
Merger and acquisition costs		$ 1,100
Recent Real Estate Acquisitions | Skilled Nursing/Transitional Care
Business Acquisition [Line Items]
Number of real estate properties acquired | Facilitiy	22	1
Recent Real Estate Acquisitions | Senior Housing
Business Acquisition [Line Items]
Number of real estate properties acquired	2	3
Care Capital Properties
Business Acquisition [Line Items]
Merger and acquisition costs	$ 30,200