IMPAIRMENT OF REAL ESTATE, ASSETS HELD FOR SALE AND DISPOSITIONS (Details) $ in Thousands		3 Months Ended
	Apr. 01, 2019 USD ($) facility	Mar. 31, 2019 USD ($) facility	Mar. 31, 2018 USD ($) facility	Jan. 31, 2019 facility	Dec. 31, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate impairment		$ 103,134	$ 532
Assets held for sale, net		270,780			$ 0
Skilled Nursing Transitional Care Facilities and Senior Housing Facilities | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities sold | facility	29
Aggregate sale price of facility	$ 282,600
Skilled Nursing Transitional Care Facilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate impairment		$ 10,900
Number of real estate properties impaired | facility		4
Number of facilities expected to be sold | facility		28
Senior Housing Facilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities expected to be sold | facility		2
Senior Housing Facilities | Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities sold with related impairment | facility			1
Senior Care Centers Sale Facilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate impairment		$ 92,200
Senior Care Centers Sale Facilities | Skilled Nursing Transitional Care Facilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities expected to be sold | facility				26
Senior Care Centers Sale Facilities | Skilled Nursing Transitional Care Facilities | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties expected to be sold | facility	3
Senior Care Centers Sale Facilities | Senior Housing Facilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities expected to be sold | facility				2
Senior Care Centers Sale Facilities | Senior Care Centers | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities sold | facility	28
Aggregate sale price of facility	$ 282,500
2019 Dispositions | Skilled Nursing Transitional Care Facilities | Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities sold | facility		3
Aggregate sale price of facility		$ 6,900
Carrying value of assets and liabilities of facility		8,400
Net loss on sale		1,500
Net income from facilities		$ 500	$ 17
2018 Dispositions | Skilled Nursing Transitional Care Facilities | Dispositions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of facilities sold | facility			1
Aggregate sale price of facility			$ 6,800
Carrying value of assets and liabilities of facility			7,200
Net loss on sale			400
Net income from facilities			100
Selling expenses			$ 100