Supplemental Financial Data - Computer Software and Goodwill (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 07, 2019	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Computer software
Balance at beginning of period		$ 437.0	[1]	$ 382.2
Acquisitions		79.3		0.0
Additions at cost		173.9		114.5
Amortization	$ (6.8)	(113.3)		(71.4)		$ (50.6)
Write-off		(4.3)		(1.0)
Other		(15.2)		12.7
Balance at end of period		557.4		437.0	[1]	382.2
Goodwill
Balance at beginning of period		2,857.9	[1]	2,841.7
Acquisition		675.6		10.9
Other		(40.2)		5.3
Balance at end of period		$ 3,493.3		$ 2,857.9	[1]	$ 2,841.7

[1] See discussion in Note 1 - Basis of Presentation and Description of Business for further detail regarding the elimination of the International lag reporting.