Goodwill and Other Assets Schedule of Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,047.7		$ 1,085.9
Accumulated amortization	(637.0)		(637.3)
Net carrying amount	410.7		448.6
Payments to Develop Software	5.9	$ 5.1
Amortization of internally-developed software	$ (6.0)	(7.8)
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	4 years 10 months 24 days
Gross carrying amount	$ 728.1		762.0
Accumulated amortization	(357.7)		(354.1)
Net carrying amount	$ 370.4		407.9
Internally-developed software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Gross carrying amount	$ 198.7		198.0
Accumulated amortization	(160.9)		(160.0)
Net carrying amount	37.8	43.3	38.0	$ 46.0
Transfer To Held For Sale	(1.0)	(1.1)
Finite-Lived Intangible Assets, Translation and Purchase Accounting Adjustments	$ 0.9	$ 1.1
Development costs non-software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	1 year 9 months 18 days
Gross carrying amount	$ 53.6		56.1
Accumulated amortization	(53.3)		(55.8)
Net carrying amount	$ 0.3		0.3
Other intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 3 months 18 days
Gross carrying amount	$ 67.3		69.8
Accumulated amortization	(65.1)		(67.4)
Net carrying amount	2.2		2.4
Other intangible asset, net [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	319.6		323.9
Accumulated amortization	(279.3)		(283.2)
Net carrying amount	$ 40.3		$ 40.7