CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 72.6	$ 97.7	$ 206.0	$ 310.0
Cost of sales	69.8	69.4	178.4	215.2
Gross margin	2.8	28.3	27.6	94.8
Selling, general and administrative expenses	10.0	10.2	31.1	29.2
Research and development expenses	1.0	0.9	2.8	2.5
Restructuring and other charges	4.4	0.9	10.1	4.8
Separation-related costs	0.6	2.5	0.8	5.4
Total costs and expenses	85.8	83.9	223.2	257.1
(Loss)/income from operations before loss on debt extinguishment, equity in net loss of unconsolidated affiliate, interest expense, net and income taxes	(13.2)	13.8	(17.2)	52.9
Loss on debt extinguishment	0.0	0.0	0.1	0.0
Equity in net loss of unconsolidated affiliate	0.1	0.0	0.4	0.0
Interest expense, net	2.0	0.0	2.0	0.0
(Loss)/income from operations before income taxes	(15.3)	13.8	(19.7)	52.9
Income tax (benefit)/expense	(3.5)	(4.2)	(5.8)	2.5
Net (loss)/income	$ (11.8)	$ 18.0	$ (13.9)	$ 50.4
Net (loss)/income per weighted average share - basic (in dollars per share)	$ (0.08)	$ 0.12	$ (0.10)	$ 0.35
Net (loss)/income per weighted average share - diluted (in dollars per share)	$ (0.08)	$ 0.12	$ (0.10)	$ 0.34
Weighted average common shares outstanding - basic (in shares)	146.3	146.0	146.2	146.0
Weighted average common shares outstanding - diluted (in shares)	146.3	146.5	146.2	146.4