Statements of Consolidated Income - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales		$ 1,514.1	$ 1,585.9	$ 1,397.5
Cost of products sold, excluding depreciation and amortization and other items	[1]	1,215.2	1,300.7	1,085.9
Costs and expenses:
Depreciation and amortization		49.1	43.9	39.7
Selling, general, administrative, research and development		98.0	96.3	97.5
Goodwill impairment		25.2	0.0	18.4
Other operating charges, net		0.9	1.4	0.8
Total costs and expenses		1,388.4	1,442.3	1,242.3
Operating income		125.7	143.6	155.2
Other expense:
Interest expense		(24.6)	(22.7)	(22.2)
Other expense, net – Note 12		(20.7)	(0.9)	0.0
Income before income taxes		80.4	120.0	133.0
Income tax provision		(18.4)	(28.3)	(87.6)
Net income		$ 62.0	$ 91.7	$ 45.4
Net income per common share:
Basic (in dollars per share)		$ 3.88	$ 5.53	$ 2.67
Diluted (in dollars per share)		$ 3.83	$ 5.43	$ 2.63
Weighted-average number of common shares outstanding (in thousands):
Basic (in shares)		15,997	16,585	16,996
Diluted (in shares)		16,203	16,874	17,259
Dividends declared per common share (in dollars per share)		$ 2.40	$ 2.20	$ 2.00

[1] See Note 8 for discussion of our adoption of ASU 2017-12 (as defined in Note 1) in 2018 and the related reclassification of amounts in 2017 that were presented in the Statements of Consolidated Income within Unrealized (gain) loss on derivative instruments and are now presented within Cost of products sold, excluding depreciation and amortization and other items ("Cost of products sold").