REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total Revenue	$ 168,584
Gross profit	55,048	$ 64,874
Bad debt expense	0	$ 7,042
Allowance for doubtful accounts	0		$ 37,912
Calculated under Revenue Guidance in Effect before Topic 606
Disaggregation of Revenue [Line Items]
Total Revenue	174,000
Gross profit	60,500
Bad debt expense	5,500
Allowance for doubtful accounts	41,200
Commercial
Disaggregation of Revenue [Line Items]
Total Revenue	140,541
Government
Disaggregation of Revenue [Line Items]
Total Revenue	26,542
Patient
Disaggregation of Revenue [Line Items]
Total Revenue	$ 1,501
Referral Bonuses | Total Revenue
Disaggregation of Revenue [Line Items]
Percentage of concentration risk, less than	1.00%