Statements of Consolidated Income (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net sales	$ 374.9			$ 393.1			$ 1,145.4	$ 1,196.5
Costs and expenses:
Cost of products sold, excluding depreciation and amortization and other items	298.6			323.3			917.2	983.4
Depreciation and amortization	12.3			11.0			36.3	32.4
Selling, general, administrative, research and development	23.3			23.9			75.7	73.9
Other operating charges, net	0.0			0.0			0.1	0.1
Total costs and expenses	334.2			358.2			1,029.3	1,089.8
Operating income	40.7			34.9			116.1	106.7
Other (expense) income:
Interest expense	(5.8)			(5.7)			(17.3)	(17.0)
Other (expense) income, net	(0.8)			0.7			(0.4)	0.3
Income before income taxes	34.1			29.9			98.4	90.0
Income tax provision	(8.7)			(8.2)			(25.8)	(21.9)
Net income	$ 25.4	$ 19.2	$ 28.0	$ 21.7	$ 20.7	$ 25.7	$ 72.6	$ 68.1
Net income per common share:
Basic (in dollars per share)	$ 1.59			$ 1.31			$ 4.52	$ 4.09
Diluted (in dollars per share)	$ 1.57			$ 1.29			$ 4.47	$ 4.03
Weighted-average number of common shares outstanding:
Basic (shares)	15,956			16,573			16,042	16,654
Diluted (shares)	16,125			16,783			16,235	16,882