Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net sales	$ 280.0	$ 203.2	$ 531.9	$ 451.9
Cost of goods sold	175.1	135.4	339.5	292.8
Gross profit	104.9	67.8	192.4	159.1
Selling, general and administrative expenses	60.0	33.0	114.2	67.8
Change in fair value of contingent consideration	(9.7)		(9.5)
(Gain) related to sale of fixed and intangible assets		(14.1)		(14.1)
Equity (earnings) from joint venture	(23.7)	(13.5)	(44.7)	(33.0)
Operating income	78.3	62.4	132.4	138.4
Interest expense	5.6	5.9	11.3	12.6
Other non-operating (income) expense, net	(1.6)	(4.4)	(2.9)	365.0
Earnings (loss) from continuing operations before income taxes	74.3	60.9	124.0	(239.2)
Income tax expense (benefit)	19.2	11.4	31.4	(66.1)
Earnings (loss) from continuing operations	55.1	49.5	92.6	(173.1)
Gain (loss) from disposal of discontinued businesses, net of tax expense (benefit) of $-, $-, $1.7 and ($1.4)		0.8	(2.1)	(2.8)
Net earnings (loss) from discontinued operations		0.8	(2.1)	(2.8)
Net earnings (loss)	55.1	50.3	90.5	(175.9)
Other comprehensive income, net of tax:
Foreign currency translation adjustments	0.5	0.1	1.1	(2.0)
Derivative gain (loss), net	1.1	(2.0)	4.9	(13.8)
Pension and postretirement adjustments	0.2	(0.7)	0.4	287.6
Total other comprehensive income (loss)	1.8	(2.6)	6.4	271.8
Total comprehensive income	$ 56.9	$ 47.7	$ 96.9	$ 95.9
Earnings (loss) per share of common stock, continuing operations:
Basic	$ 1.15	$ 1.03	$ 1.93	$ (3.61)
Diluted	1.14	1.03	1.92	(3.61)
Earnings (loss) per share of common stock, discontinued operations:
Basic		0.02	(0.04)	(0.06)
Diluted		0.02	(0.04)	(0.06)
Net earnings (loss) per share of common stock:
Basic	1.15	1.05	1.89	(3.67)
Diluted	$ 1.14	$ 1.05	$ 1.88	$ (3.67)
Average number of common shares outstanding:
Basic	47.7	47.8	47.8	47.9
Diluted	48.1	48.0	48.1	47.9