UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Millions		Total	Common Share Capital	Treasury Share Capital	Additional Paid in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2022			377,368,837	0
Beginning balance at Dec. 31, 2022		$ 1,441.9	$ 0.0	$ 0.0	$ 2,630.7	$ (1,142.6)	$ (46.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		50.3				50.3
Exercise of employee stock options (in shares)			246,653
Exercise of employee stock options		2.2			2.2
Stock-based compensation, net of withholding for tax (in shares)	[1]		14,730
Stock-based compensation, net of withholding for tax	[1]	5.4			5.4
Employee 401K match with Vertiv stock (in shares)			135,245
Employee 401K match with Vertiv stock		2.1			2.1
Exercise of warrants (in shares)	[2]		1,368,194
Exercise of warrants	[2]	21.6			21.6
Other comprehensive income (loss), net of tax		27.3					27.3
Ending balance (in shares) at Mar. 31, 2023			379,133,659	0
Ending balance at Mar. 31, 2023		$ 1,550.8	$ 0.0	$ 0.0	2,662.0	(1,092.3)	(18.9)
Beginning balance (in shares) at Dec. 31, 2023		381,788,876	381,788,876	0
Beginning balance at Dec. 31, 2023		$ 2,014.9	$ 0.0	$ 0.0	2,711.3	(691.9)	(4.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(5.9)				(5.9)
Exercise of employee stock options (in shares)			1,109,113
Exercise of employee stock options		14.4			14.4
Stock-based compensation, net of withholding for tax (in shares)	[3]		102,833
Stock-based compensation, net of withholding for tax	[3]	17.3			17.3
Employee 401K match with Vertiv stock (in shares)			44,968
Employee 401K match with Vertiv stock		2.2			2.2
Dividends		(9.3)				(9.3)
Repurchases of common stock (in shares)			(9,076,444)	(9,076,444)
Repurchase of common stock		(605.9)		$ (605.9)
Other comprehensive income (loss), net of tax		$ (34.3)					(34.3)
Ending balance (in shares) at Mar. 31, 2024		373,969,346	373,969,346	9,076,444
Ending balance at Mar. 31, 2024		$ 1,393.4	$ 0.0	$ (605.9)	$ 2,745.2	$ (707.1)	$ (38.8)

[1] Net stock compensation activity includes 14,730 shares withheld for taxes valued at $0.1 and stock-based compensation of $5.5.

[2] On February 24, 2023, GS Sponsor LLC elected to exercise 5,266,666 warrants on a cashless basis pursuant to the agreement governing the warrants, in exchange for which the Company issued 1,368,194 shares of Class A common stock.

[3] Net stock compensation activity includes 146,095 vested shares offset by 43,262 shares withheld for taxes valued at $3.0 and stock-based compensation of $9.2.