Affiliated Companies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Purchases and royalty payments made to affiliates	$ 24.6	$ 23.1
Amount due and payable to affiliates	17.2		$ 12.9
Sales to affiliates	2.2	$ 2.4
Amount receivable from affiliates	1.4		1.6
Carrying amount, equity-method investments	81.5		77.8
Carrying amount, cost-method investments	$ 13.4		$ 13.4