NET REVENUE AND ACCOUNTS RECEIVABLE - Aging of Accounts Receivable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 114,864,000	$ 123,434,000
Allowance for doubtful accounts	0	(37,912,000)
Accounts receivable, net	114,864,000	85,522,000
Government
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	23,947,000	30,684,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	82,028,000	82,546,000
Patient
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	8,889,000	10,204,000
0 - 180 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	87,229,000	86,946,000
0 - 180 days | Government
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	17,849,000	20,602,000
0 - 180 days | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	67,288,000	63,767,000
0 - 180 days | Patient
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	2,092,000	2,577,000
Over 180 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	27,635,000	36,488,000
Over 180 days | Government
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	6,098,000	10,082,000
Over 180 days | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	14,740,000	18,779,000
Over 180 days | Patient
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 6,797,000	$ 7,627,000
Accounts Receivable | Allowance for doubtful accounts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk, percentage	0.00%	30.70%