BUSINESS ACQUISITIONS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Business Combinations [Abstract]
Payments to Acquire Businesses, Net of Cash Acquired	$ 259.2	$ (0.2)
Business Acquisition [Line Items]
Goodwill, Acquired During Period	141.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	(311.0)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(21.8)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	289.2	0.0
Business Acquisition, Pro Forma Revenue	3,191.1	3,106.0
Business Acquisition, Pro Forma Net Income (Loss)	227.5	216.2
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets	8.1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	1.8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	(159.4)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	0.0
Payments to Acquire Businesses, Net of Cash Acquired	259.2	(0.2)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	13.7
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	259.2
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory	0.0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment	0.0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Previous Period	0.0
Escrow Deposit	30.0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles	7.4
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets	0.0	(10.4)
Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Lease Obligation	8.1
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities	0.0	(10.4)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	0.0	0.2
Estimated amortization expense, 2012	183.3
Accrued Liabilities [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities		(8.4)
Other Noncurrent Liabilities [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities	0.0	(2.0)
Operating lease liability
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities	0.0
Goodwill [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles		(30.5)
Other Intangible Assets
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles		$ 19.9
Goodwill [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Previous Period	(7.4)
Other Noncurrent Assets [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Previous Period	0.0
Other acquirees
Business Combinations [Abstract]
Finite-lived Intangible Assets Acquired	159.4
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	159.4
Goodwill, Acquired During Period	141.7
Providence Medical Foundation
Business Acquisition [Line Items]
Goodwill, Acquired During Period	25.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	(55.8)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	(0.9)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(0.9)
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets	0.9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	29.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	0.0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	54.9
Escrow Deposit	0.0
Westpac Labs, Inc.
Business Acquisition [Line Items]
Goodwill, Acquired During Period	45.1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	(97.7)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(10.0)
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	1.8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	50.8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	10.0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	87.7
Escrow Deposit	0.0
Cash Acquired in Excess of Payments to Acquire Business	0.0
Baystate Medical Center
Business Acquisition [Line Items]
Goodwill, Acquired During Period	70.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	(157.5)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	(7.2)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(10.9)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	146.6
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets	7.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	79.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	3.7
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	116.6
Escrow Deposit	30.0
Cash Acquired in Excess of Payments to Acquire Business	0.0
Other Acquisitions
Business Acquisition [Line Items]
Escrow Deposit	$ 0.0
Customer Lists | Maximum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Customer Lists | Minimum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years