VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Tax Credit Carryforward [Line Items]
Tax credits, valuation allowance	$ 46,200		$ 32,100
Allowance For Doubtful Accounts [Member]
Valuation and qualifying accounts [Roll forward]
Balance at Beginning of Period	26,470		26,501		$ 17,728
Acquisition of Emeritus	0		0		11,087
Charged to costs and expenses	30,632		25,132		20,509
Charged to other accounts	2,680		2,135		771
Deductions	(32,738)		(27,298)		(23,594)
Balance at End of Period	27,044		26,470		26,501
Deferred Tax Valuation Allowance [Member]
Valuation and qualifying accounts [Roll forward]
Balance at Beginning of Period	121,602		9,213		72,366
Acquisition of Emeritus	0		0		1,002
Charged to costs and expenses	142,862	[1]	111,797	[2]	0
Charged to other accounts	0		592	[2]	0
Deductions	(159)	[3]	0		(64,155)	[4]
Balance at End of Period	264,305		121,602		9,213
State [Member]
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Change in Amount					$ (64,155)
Federal net operating losses [Member]
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Change in Amount	128,931		81,968
Federal credits [Member]
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Change in Amount	$ 13,931		$ 30,421

[1] Adjustment to valuation allowance for federal and state net operating losses and federal credits of $128,931 and $13,931, respectively.

[2] Adjustment to valuation allowance for federal and state net operating losses and federal credits of $81,968 and $30,421, respectively.

[3] Prior year adjustment related to state valuation allowance.

[4] Adjustment to valuation allowance for federal and state net operating losses and federal credits of $(64,155).