Segment Data - Schedule of summarized financial information by segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total Revenue	$ 1,743.6	$ 2,121.7	$ 3,639.0	$ 4,024.7
Percent change in revenue amount	(18.00%)		(10.00%)
Americas
Segment Reporting Information [Line Items]
Total Revenue	$ 1,248.5	1,492.9	$ 2,643.3	2,840.5
EMEA
Segment Reporting Information [Line Items]
Total Revenue	205.1	228.9	415.1	431.5
APAC
Segment Reporting Information [Line Items]
Total Revenue	290.0	399.9	580.6	752.7
Operating segments | Americas
Segment Reporting Information [Line Items]
Total Revenue	$ 1,248.5	1,492.9	$ 2,643.3	2,840.5
Percent change in revenue amount	(16.00%)		(7.00%)
Acquisition related costs and efficiency initiatives	$ 53.8	122.5	$ 117.9	192.8
Percent change in adjusted EBIDTA	(56.00%)		(39.00%)
Operating segments | EMEA
Segment Reporting Information [Line Items]
Total Revenue	$ 205.1	228.9	$ 415.1	431.5
Percent change in revenue amount	(10.00%)		(4.00%)
Acquisition related costs and efficiency initiatives	$ 26.1	15.4	$ 22.7	15.2
Percent change in adjusted EBIDTA	69.00%		49.00%
Operating segments | APAC
Segment Reporting Information [Line Items]
Total Revenue	$ 290.0	399.9	$ 580.6	752.7
Percent change in revenue amount	(27.00%)		(23.00%)
Acquisition related costs and efficiency initiatives	$ 38.9	$ 36.6	$ 48.5	$ 54.9
Percent change in adjusted EBIDTA	6.00%		(12.00%)