REVENUE RECOGNITION AND ALLOWANCE FOR CREDIT LOSSES (Details)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Percentage of net revenues	100.00%	100.00%
Net accounts receivable	100.00%		100.00%
DIS business
Segment Reporting Information [Line Items]
Percentage of net revenues	96.00%	96.00%
Net accounts receivable	95.00%		95.00%
DIS business | Healthcare Insurers
Segment Reporting Information [Line Items]
Percentage of net revenues	37.00%	37.00%
Net accounts receivable	22.00%		22.00%
DIS business | Healthcare Insurers | Fee-for-service
Segment Reporting Information [Line Items]
Percentage of net revenues	34.00%	33.00%
DIS business | Healthcare Insurers | Capitated
Segment Reporting Information [Line Items]
Percentage of net revenues	3.00%	4.00%
DIS business | Government Payers
Segment Reporting Information [Line Items]
Percentage of net revenues	14.00%	15.00%
Net accounts receivable	10.00%		11.00%
DIS business | Client Payers
Segment Reporting Information [Line Items]
Percentage of net revenues	33.00%	31.00%
Net accounts receivable	42.00%		42.00%
DIS business | Patients
Segment Reporting Information [Line Items]
Percentage of net revenues	12.00%	13.00%
Net accounts receivable	21.00%		20.00%
DIS business | Minimum
Segment Reporting Information [Line Items]
Percentage of net revenues	95.00%	95.00%
All other operating segments | DS Businesses
Segment Reporting Information [Line Items]
Percentage of net revenues	4.00%	4.00%
Net accounts receivable	5.00%		5.00%