Affiliated Companies (Textuals) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Unremitted income of affiliated companies	$ 69.9	$ 63.0	$ 56.2
Dividends received from affiliated companies	2.2	1.4	0.8
Purchases and royalty payments made to affiliates	86.7	94.5	65.8
Amount due and payable to affiliates	12.4	9.0
Sales to affiliates	8.1	6.8	5.3
Amount receivable from affiliates	1.3	0.9
Equity method investments	72.4	69.3
Cost method investment	13.4	13.4
Cost method investments, original cost	8.4
Daikyo Seiko, Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Equity in unrealized (gains) losses in securities available-for-sale and derivative instruments	$ (0.5)	$ (5.3)	$ (5.4)