Goodwill and Intangible Assets, net - Other Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Other Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 1,050.8	$ 613.4
Accumulated Amortization	(238.7)	(206.8)
Total intangible assets	1,104.3	667.2
Tradenames and other
Other Intangible Assets [Line Items]
Indefinite-lived intangible assets (excluding goodwill)	53.5	53.8
Patents, tradenames and trademarks
Other Intangible Assets [Line Items]
Finite-lived intangible assets, gross	205.3	151.4
Accumulated Amortization	(54.6)	(50.1)
Customer/agent relationships and other
Other Intangible Assets [Line Items]
Finite-lived intangible assets, gross	845.5	462.0
Accumulated Amortization	$ (184.1)	$ (156.7)