CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 447.5	$ 397.6	$ 863.2	$ 785.3
Cost of goods and services sold	305.3	272.6	586.6	526.1
Gross profit	142.2	125.0	276.6	259.2
Research and development	10.8	10.0	20.4	20.3
Selling, general and administrative expenses	70.0	61.3	138.3	123.8
Other expense (Note 13)	1.1	11.7	4.2	12.6
Operating profit	60.3	42.0	113.7	102.5
Interest expense	2.2	2.2	4.1	4.3
Interest income	(0.3)	(0.3)	(0.9)	(0.6)
Other nonoperating income	(1.7)	(0.6)	(3.3)	(1.4)
Income before income taxes	60.1	40.7	113.8	100.2
Income tax expense	6.0	2.9	18.5	5.1
Equity in net income of affiliated companies	(2.0)	(1.0)	(4.4)	(4.6)
Net income	$ 56.1	$ 38.8	$ 99.7	$ 99.7
Net income per share:
Basic (in dollars per share)	$ 0.76	$ 0.53	$ 1.35	$ 1.35
Diluted (in dollars per share)	$ 0.75	$ 0.51	$ 1.33	$ 1.32
Weighted average shares outstanding:
Basic (in shares)	73.6	73.9	73.8	73.6
Diluted (in shares)	75.0	75.8	75.2	75.7
Dividends declared per share	$ 0.14	$ 0.13	$ 0.28	$ 0.26