PROPERTIES (MedEquities Merger) (Narrative) (Detail) $ / shares in Units, $ in Thousands, shares in Millions			3 Months Ended								7 Months Ended	12 Months Ended
	Oct. 31, 2019 USD ($) facility	May 17, 2019 USD ($) loan item facility $ / shares shares	Dec. 31, 2019 USD ($) state facility	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) state facility	Dec. 31, 2019 USD ($) state facility	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Consideration												$ 1,325,400	$ 105,700	$ 412,700
Cash payment to acquire facilities	$ 369,000
Number of real estate properties | facility			987								987	987
Number of states | state			40								40	40
Acquisition related costs												$ 5,115	383
Revenues			$ 246,668	$ 233,195	$ 225,279	$ 223,688	$ 219,750	$ 221,852	$ 219,881	$ 220,199		$ 928,830	$ 881,682	$ 908,385
MedEquities
Business Acquisition [Line Items]
Business combination acquirees' stockholders conversion ratio of acquirer's stock received		0.235
Business combination acquirees stockholder's additional cash amount per share received | $ / shares		$ 2.00
Cash payment to acquire facilities		$ 63,700
Number of shares issued | shares		7.5
Special cash dividend (per share) | $ / shares		$ 0.21
Loan amount		$ 350,000
Mortgage loans on real estate, number of loans | loan		4
Number of other investments acquired | item		3
Number of unconsolidated joint ventures acquired | item		1
Consideration		$ 346,000
Acquisition related costs											$ 5,100
Revenues											$ 35,200
Facilities Acquired [Member]
Business Acquisition [Line Items]
Number of real estate properties | facility	60
Facilities Acquired [Member] | MedEquities
Business Acquisition [Line Items]
Number of real estate properties | facility		33