Goodwill and Intangible Assets - Intangible Assets Subject to Amortization (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 1,391.8	$ 1,392.7
Accumulated Amortization	(565.3)	(552.7)
Net Book Value	826.5	840.0
Customer lists
Finite-Lived Intangible Assets
Gross Carrying Amount	933.5	959.1
Accumulated Amortization	(359.6)	(351.4)
Net Book Value	573.9	607.7
Developed technology
Finite-Lived Intangible Assets
Gross Carrying Amount	371.9	380.5
Accumulated Amortization	(199.5)	(194.8)
Net Book Value	172.4	185.7
Tradenames
Finite-Lived Intangible Assets
Gross Carrying Amount	86.4	51.5
Accumulated Amortization	(6.2)	(4.9)
Net Book Value	80.2	46.6
Non-compete agreements
Finite-Lived Intangible Assets
Gross Carrying Amount	0.0	1.6
Accumulated Amortization	0.0	(1.6)
Net Book Value	$ 0.0	$ 0.0