REVENUE (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019	Jun. 30, 2020 USD ($) performance_obligation	Jun. 30, 2019	Dec. 31, 2019 USD ($)
Disaggregation of Revenue [Line Items]
Number of performance obligations | performance_obligation			1
Percentage of receivable under government’s bundled payment system	80.00%		80.00%
Amounts pending approval from third-party payors associated with Medicare recovery claims	$ 20,541		$ 20,541		$ 17,509
Patient care service revenue	100.00%	100.00%	100.00%	100.00%
Medicare and Medicare Advantage
Disaggregation of Revenue [Line Items]
Patient care service revenue	69.00%	70.00%	69.00%	70.00%
Commercial and other
Disaggregation of Revenue [Line Items]
Patient care service revenue	26.00%	26.00%	27.00%	25.00%
Medicaid and Managed Medicaid
Disaggregation of Revenue [Line Items]
Patient care service revenue	4.00%	4.00%	4.00%	4.00%
Other
Disaggregation of Revenue [Line Items]
Patient care service revenue	1.00%	0.00%	0.00%	1.00%
Prepaid expenses and other current assets
Disaggregation of Revenue [Line Items]
Amounts pending approval from third-party payors associated with Medicare recovery claims	$ 4,956		$ 4,956		9,284
Other long-term assets
Disaggregation of Revenue [Line Items]
Amounts pending approval from third-party payors associated with Medicare recovery claims	$ 15,585		$ 15,585		$ 8,225