ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Activity in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,417.7	$ 512.1	$ (704.8)	[1]
Other comprehensive income (loss), net of tax	(81.8)	(15.9)	33.4
Ending balance	1,441.9	1,417.7	512.1
Recognized earnings	$ (2.4)	$ 10.5	$ 6.4
Non-U.S. Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 39.8	$ 104.9	$ 32.9
Other comprehensive income (loss), net of tax	(196.8)	(65.1)	72.0
Ending balance	(157.0)	39.8	104.9
Interest Rate Swap
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	8.7	(32.8)	0.0
Other comprehensive income (loss), net of tax	101.5	41.5	(32.8)
Ending balance	110.2	8.7	(32.8)
Pension
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(12.9)	(19.7)	(14.8)
Other comprehensive income (loss), net of tax	13.5	6.8	(4.9)
Ending balance	0.6	(12.9)	(19.7)
Tax Receivable Agreement
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0.0	(0.9)	0.0
Other comprehensive income (loss), net of tax	0.0	(3.2)	(0.9)
TRA settlement	$ 0.0	$ 4.1	$ 0.0
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Tax receivable agreement	Tax receivable agreement	Tax receivable agreement
Ending balance	$ 0.0	$ 0.0	$ (0.9)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	35.6	51.5	18.1	[1]
Ending balance	$ (46.2)	$ 35.6	$ 51.5

[1] The shares and earnings per share available to holders of the Company’s common shares, prior to the Business Combination, have been recasted as shares reflecting the exchange ratio established in the Business Combination (1.0 Vertiv Holdings share to 118.261955 Vertiv Holdings Co shares).