REVENUE RECOGNITION (Details)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
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	97.00%	97.00%
Net accounts receivable	96.00%		97.00%
DIS business | Healthcare Insurers
Segment Reporting Information [Line Items]
Percentage of net revenues	41.00%	40.00%
Net accounts receivable	29.00%		32.00%
DIS business | Healthcare Insurers | Fee-for-service
Segment Reporting Information [Line Items]
Percentage of net revenues	39.00%	38.00%
DIS business | Healthcare Insurers | Capitated
Segment Reporting Information [Line Items]
Percentage of net revenues	2.00%	2.00%
DIS business | Government Payers
Segment Reporting Information [Line Items]
Percentage of net revenues	11.00%	10.00%
Net accounts receivable	6.00%		6.00%
DIS business | Client Payers
Segment Reporting Information [Line Items]
Percentage of net revenues	32.00%	35.00%
Net accounts receivable	41.00%		38.00%
DIS business | Patients (including coinsurance and deductible responsibilities)
Segment Reporting Information [Line Items]
Percentage of net revenues	13.00%	12.00%
Net accounts receivable	20.00%		21.00%
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	3.00%	3.00%
Net accounts receivable	4.00%		3.00%