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BUSINESS ACQUISITIONS - Additional Information (Details) $ in Millions, $ in Millions				3 Months Ended		9 Months Ended
	Aug. 04, 2025 USD ($)	Aug. 23, 2024 CAD ($)	Aug. 23, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Aug. 31, 2025
Business Combination [Line Items]
Cash paid for business acquisitions				$ 34	$ 1,583	$ 51	$ 1,831
Corewell Health
Business Combination [Line Items]
Subsidiary, ownership percentage, parent								51.00%
Laboratory Facility \| Corewell Health
Business Combination [Line Items]
Ownership percentage								49.00%
LifeLabs Inc.
Business Combination [Line Items]
Cash paid for business acquisitions		$ 1,350	$ 1,000
Deferred tax asset, increase						9
Goodwill, decrease						$ 9
Spectra Laboratories
Business Combination [Line Items]
Cash paid for business acquisitions	$ 34
Goodwill, expected tax deductible amount	25
Spectra Laboratories \| Customer Relationships
Business Combination [Line Items]
Intangible assets	$ 9
Intangible assets, useful life	15 years