REVENUE FROM CONTRACTS WITH CUSTOMERS - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2023	Sep. 24, 2022	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Percentage of unbilled revenue billed during period	90.00%	85.00%
Amount of unbilled revenue billed during period	$ 204.0	$ 161.0
Percentage of contract liabilities recognized as revenue during period	80.00%	85.00%
Contract with customer, liability, revenue recognized, including opening balance	$ 290.0
Amount of contract liabilities recognized as revenue		$ 240.0
Unpaid advanced client billings	52.0		$ 54.0
Accounts receivable, credit loss expense (reversal)	10.2	$ 4.4
Performance obligations expected to be satisfied	$ 957.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, percentage	50.00%
Performance obligations expected to be satisfied, expected timing	12 months

Contract With Customer, Asset, Percentage Of Amount Reclassified To Receivable

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- Definition

Contract with Customer, Liability, Revenue Recognized, Including Opening Balance

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Contract With Customer, Percentage Of Liabilities, Recognized As Revenue

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- Definition

Contract With Customer, Unpaid Advanced Client Billings

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- Definition

Amount of decrease in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time from transfer to receivable due to right to consideration becoming unconditional.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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