REVENUE (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) performance_obligation	Mar. 31, 2019	Dec. 31, 2019 USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Number of performance obligations | performance_obligation	1
Percentage of receivable under government’s bundled payment system	80.00%
Medicare bad debt claims	$ 20,739		$ 17,509
Patient care service revenue	100.00%	100.00%
Medicare and Medicare Advantage
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient care service revenue	68.00%	70.00%
Commercial and other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient care service revenue	27.00%	25.00%
Medicaid and Managed Medicaid
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient care service revenue	5.00%	4.00%
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient care service revenue	0.00%	1.00%
Prepaid expenses and other current assets
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Medicare bad debt claims	$ 9,404		9,284
Other long-term assets
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Medicare bad debt claims	$ 11,335		$ 8,225