Goodwill and Intangible Assets, net - Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Other Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 1,057.0	$ 613.4
Accumulated Amortization	(221.4)	(206.8)
Total intangible assets	1,110.9	667.2
Tradenames and other
Other Intangible Assets [Line Items]
Indefinite-lived intangible assets (excluding goodwill)	53.9	53.8
Patents, tradenames and trademarks
Other Intangible Assets [Line Items]
Finite-lived intangible assets, gross	206.5	151.4
Accumulated Amortization	(52.2)	(50.1)
Customer/agent relationships and other
Other Intangible Assets [Line Items]
Finite-lived intangible assets, gross	850.5	462.0
Accumulated Amortization	$ (169.2)	$ (156.7)