Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 512.1	$ (704.8)	[1]	$ (540.3)	[1]
Other comprehensive income (loss), net of tax	(15.9)	33.4		(23.7)
TRA settlement	(7.7)	(22.2)
Ending balance	1,417.7	512.1		(704.8)	[1]
Recognized earnings	10.5	6.4
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	104.9	32.9		43.2
Other comprehensive income (loss), net of tax	(65.1)	72.0		(10.3)
Ending balance	39.8	104.9		32.9
Interest Rate Swap
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(32.8)	0.0		0.0
Other comprehensive income (loss), net of tax	41.5	(32.8)		0.0
Ending balance	8.7	(32.8)		0.0
Pension
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(19.7)	(14.8)		(1.4)
Other comprehensive income (loss), net of tax	6.8	(4.9)		(13.4)
Ending balance	(12.9)	(19.7)		(14.8)
Tax Receivable Agreement
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(0.9)	0.0		0.0
Other comprehensive income (loss), net of tax	(3.2)	(0.9)		0.0
TRA settlement	4.1	0.0		0.0
Ending balance	0.0	(0.9)		0.0
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	51.5	18.1	[1]	41.8	[1]
Ending balance	$ 35.6	$ 51.5		$ 18.1	[1]

[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).