Goodwill and Other Assets Schedule of Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,050.1	$ 1,007.7
Accumulated amortization	(600.6)	(505.4)
Net carrying amount	$ 449.5	502.3
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years 4 months 24 days
Gross carrying amount	$ 727.0	698.7
Accumulated amortization	(318.5)	(251.0)
Net carrying amount	$ 408.5	447.7
Internally-developed software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	1 year 3 months 18 days
Gross carrying amount	$ 192.4	178.2
Accumulated amortization	(155.3)	(132.2)
Net carrying amount	$ 37.1	46.0
Development costs non-software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 months 6 days
Gross carrying amount	$ 53.5	51.5
Accumulated amortization	(53.2)	(47.5)
Net carrying amount	$ 0.3	4.0
Other intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years 3 months 18 days
Gross carrying amount	$ 77.2	79.3
Accumulated amortization	(73.6)	(74.7)
Net carrying amount	3.6	4.6
Other intangible asset, net [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	323.1	309.0
Accumulated amortization	(282.1)	(254.4)
Net carrying amount	$ 41.0	$ 54.6