Goodwill and Other Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Indefinite-lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 45.4	$ 48.0	$ 87.9	$ 95.3
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, accumulated amortization	(882.0)		(882.0)		$ (833.7)
Gross Value	1,905.8		1,905.8		1,896.3
Accumulated Amortization	(882.0)		(882.0)		(833.7)
Net Value	1,023.8		1,023.8		1,062.6
C&W trade name
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	546.0		546.0		546.0
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	1,342.9		1,342.9		1,333.1
Finite-lived intangible assets, accumulated amortization	(874.4)		(874.4)		(827.5)
Finite-lived intangible assets, net value	468.5		468.5		505.6
Accumulated Amortization	(874.4)		$ (874.4)		$ (827.5)
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)			1 year		1 year
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)			15 years		15 years
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	16.9		$ 16.9		$ 17.2
Finite-lived intangible assets, accumulated amortization	(7.6)		(7.6)		(6.2)
Finite-lived intangible assets, net value	9.3		9.3		11.0
Accumulated Amortization	$ (7.6)		$ (7.6)		$ (6.2)
Other intangible assets | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)			2 years		2 years
Other intangible assets | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)			13 years		13 years