Affiliated Companies (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Purchases and royalty payments made to affiliates	$ 27.6	$ 24.6	$ 52.2	$ 47.7
Amount due and payable to affiliates	22.0		22.0		$ 12.9
Sales to affiliates	2.5	$ 2.6	4.7	$ 5.0
Amount receivable from affiliates	1.5		1.5		1.6
Carrying amount, equity-method investments	82.0		82.0		77.8
Carrying amount, cost-method investments	$ 13.4		$ 13.4		$ 13.4