Segment Data - Schedule of adjusted EBITDA (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Depreciation and amortization	$ (64.9)	$ (75.0)	$ (211.5)	$ (222.8)
Interest expense, net of interest income	(44.9)	(37.4)	(120.2)	(112.8)
Benefit from income taxes	4.6	11.0	38.8	40.5
Integration and other costs related to merger	(12.8)	(29.9)	(47.6)	(74.1)
Pre-IPO stock-based compensation	(4.5)	(11.4)	(16.7)	(33.6)
Acquisition related costs and efficiency initiatives	(28.3)	(8.0)	(114.7)	(17.7)
Other	(3.6)	(6.1)	(27.5)	(13.8)
Net income (loss)	(37.3)	11.7	(193.2)	(2.9)
Operating segments | Americas
Segment Reporting Information [Line Items]
Adjusted EBITDA	81.2	125.2	199.1	318.0
Operating segments | EMEA
Segment Reporting Information [Line Items]
Adjusted EBITDA	11.5	20.3	34.2	35.5
Operating segments | APAC
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 24.4	$ 23.0	$ 72.9	$ 77.9