CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenue	$ 64.9	$ 114.0	$ 133.4	$ 212.3
Cost of sales	54.7	80.2	108.6	145.8
Gross margin	10.2	33.8	24.8	66.5
Selling, general and administrative expenses	10.3	9.8	21.1	19.0
Research and development expenses	0.8	0.8	1.8	1.6
Restructuring and other charges	0.9	3.8	5.7	3.9
Separation-related costs	0.1	1.3	0.2	2.9
Total costs and expenses	66.8	95.9	137.4	173.2
(Loss)/income from operations before loss on debt extinguishment, equity in net loss of unconsolidated affiliate and income taxes	(1.9)	18.1	(4.0)	39.1
Loss on debt extinguishment	0.1	0.0	0.1	0.0
Equity in net loss of unconsolidated affiliate	0.2	0.0	0.3	0.0
(Loss)/income from operations before income taxes	(2.2)	18.1	(4.4)	39.1
Income tax (benefit)/expense	(2.0)	2.6	(2.3)	6.7
Net (loss)/income	$ (0.2)	$ 15.5	$ (2.1)	$ 32.4
Net (loss)/income per weighted average share - basic (in dollars per share)	$ 0	$ 0.11	$ (0.01)	$ 0.22
Net (loss)/income per weighted average share - diluted (in dollars per share)	$ 0	$ 0.11	$ (0.01)	$ 0.22
Weighted average common shares outstanding - basic (in shares)	146.2	146.0	146.1	146.0
Weighted average common shares outstanding - diluted (in shares)	146.2	146.5	146.1	146.5