Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 366.0	$ 299.7
Accumulated Amortization	(93.5)	(70.8)
Net Carrying Amount	272.5	228.9
Amortization of intangible assets	27.8	17.7	$ 8.4
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2020	24.8
2021	24.4
2022	23.1
2023	22.6
2024	22.2
Indefinite-lived trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8.2	7.9
Accumulated Amortization	0.0	0.0
Net Carrying Amount	8.2	7.9
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	322.3	259.9
Accumulated Amortization	(80.3)	(58.9)
Net Carrying Amount	$ 242.0	201.0
Weighted-average amortization period	11 years 4 months 24 days
Finite-lived trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 20.7	20.3
Accumulated Amortization	(7.1)	(3.8)
Net Carrying Amount	$ 13.6	16.5
Weighted-average amortization period	6 years 2 months 12 days
Amortization of intangible assets	$ 27.8	17.7
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8.7	0.4
Accumulated Amortization	(0.8)	(0.4)
Net Carrying Amount	$ 7.9	0.0
Weighted-average amortization period	10 years 6 months
Other contract-related assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 0.0	5.7
Accumulated Amortization	0.0	(3.1)
Net Carrying Amount	0.0	2.6
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6.1	5.5
Accumulated Amortization	(5.3)	(4.6)
Net Carrying Amount	$ 0.8	$ 0.9
Weighted-average amortization period	27 days