BUSINESS ACQUISITIONS - Amortizable Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)
Business Acquisition [Line Items]
Total	$ 753
Customer-related
Business Acquisition [Line Items]
Total	$ 639
Customer-related | Minimum
Business Acquisition [Line Items]
Weighted Average Useful Life (in years)	15 years
Customer-related | Maximum
Business Acquisition [Line Items]
Weighted Average Useful Life (in years)	25 years
Trade names
Business Acquisition [Line Items]
Total	$ 99
Weighted Average Useful Life (in years)	15 years
Non-competition agreements
Business Acquisition [Line Items]
Total	$ 15
Weighted Average Useful Life (in years)	5 years
LifeLabs
Business Acquisition [Line Items]
Total	$ 434
LifeLabs | Customer-related
Business Acquisition [Line Items]
Total	335
LifeLabs | Trade names
Business Acquisition [Line Items]
Total	99
LifeLabs | Non-competition agreements
Business Acquisition [Line Items]
Total	0
Laboratory Business of Three Physician Groups in New York
Business Acquisition [Line Items]
Total	57
Laboratory Business of Three Physician Groups in New York | Customer-related
Business Acquisition [Line Items]
Total	57
Laboratory Business of Three Physician Groups in New York | Trade names
Business Acquisition [Line Items]
Total	0
Laboratory Business of Three Physician Groups in New York | Non-competition agreements
Business Acquisition [Line Items]
Total	0
Select Assets of the Outreach Laboratory Services Business of Allina Health
Business Acquisition [Line Items]
Total	55
Select Assets of the Outreach Laboratory Services Business of Allina Health | Customer-related
Business Acquisition [Line Items]
Total	55
Select Assets of the Outreach Laboratory Services Business of Allina Health | Trade names
Business Acquisition [Line Items]
Total	0
Select Assets of the Outreach Laboratory Services Business of Allina Health | Non-competition agreements
Business Acquisition [Line Items]
Total	0
OhioHealth
Business Acquisition [Line Items]
Total	54
OhioHealth | Customer-related
Business Acquisition [Line Items]
Total	54
OhioHealth | Trade names
Business Acquisition [Line Items]
Total	0
OhioHealth | Non-competition agreements
Business Acquisition [Line Items]
Total	0
Outreach Laboratory Services Business of University Hospitals
Business Acquisition [Line Items]
Total	58
Outreach Laboratory Services Business of University Hospitals | Customer-related
Business Acquisition [Line Items]
Total	43
Outreach Laboratory Services Business of University Hospitals | Trade names
Business Acquisition [Line Items]
Total	0
Outreach Laboratory Services Business of University Hospitals | Non-competition agreements
Business Acquisition [Line Items]
Total	15
Other Acquisitions
Business Acquisition [Line Items]
Total	95
Other Acquisitions | Customer-related
Business Acquisition [Line Items]
Total	95
Other Acquisitions | Trade names
Business Acquisition [Line Items]
Total	0
Other Acquisitions | Non-competition agreements
Business Acquisition [Line Items]
Total	$ 0