Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 333.8	$ 286.9	$ 964.4	$ 1,206.6
Cost of sales	267.8	273.4	783.4	997.3
Gross margin	66.0	13.5	181.0	209.3
Selling, general and administrative expenses	32.0	24.6	102.7	95.2
Research and technology expenses	10.4	10.7	33.5	36.0
Other operating expense	0.8	15.8	16.0	43.6
Operating income (loss)	22.8	(37.6)	28.8	34.5
Interest expense, net	9.5	9.7	29.1	32.4
Income (loss) before income taxes, and equity in earnings from affiliated companies	13.3	(47.3)	(0.3)	2.1
Income tax expense (benefit)	5.1	(56.9)	1.6	(48.7)
Income (loss) before equity in earnings from affiliated companies	8.2	9.6	(1.9)	50.8
Equity in earnings (losses) from affiliated companies	0.8	0.1	(0.9)	0.3
Net income (loss)	$ 9.0	$ 9.7	$ (2.8)	$ 51.1
Basic net income (loss) per common share	$ 0.11	$ 0.12	$ (0.03)	$ 0.61
Diluted net income (loss) per common share	$ 0.11	$ 0.12	$ (0.03)	$ 0.61
Weighted-average common shares:
Basic	84.1	83.8	84.1	83.7
Weighted average common shares outstanding - Dilutive (in shares)	84.7	84.0	84.1	84.0