SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Patient Accounts Receivable Narrative (Details) - day	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Concentration Risk [Line Items]
Accounts receivable derived from Medicare	60.00%	58.00%
Percentage of patient receivables outstanding	10.00%
Historical collection rate from Medicare	99.00%
Rate of request for anticipated payment submitted for the initial episode of care	20.00%
Maximum days to submit final bill from the start of episode	90
Maximum days to submit final bill from the date the request for anticipated payment was paid	60
Customer Concentration Risk | Accounts Receivable | Single Payor
Concentration Risk [Line Items]
Concentration risk (percent)	10.10%