Supplemental Financial Statement Information - (Tables)

9 Months Ended

Sep. 30, 2021

Other Income and Expenses [Abstract]

Schedule of Other Expense, Net

Other income (expense), net for the three and nine months ended September 30, 2021 and 2020 was as follows:

(in millions)	Three months ended September 30,				Nine months ended September 30,
	2021		2020		2021		2020
Rent and royalty income	$	0.2	$	0.1	$	0.7	$	0.6
Gains from disposal of property, plant and equipment, net	0.1		0.8		2.5		3.3
Net equity income (loss) on joint ventures (See Note 6)	0.4		(1.0)		0.4		(6.6)
Joint venture restructuring charges (See Note 6)	—		—		—		(2.4)
Gain from sale of business (See Note 5)	13.7		—		13.7		—
Adjustment to indemnification for conditional ARO costs	—		—		—		4.3
Other	0.1		(0.3)		0.1		—
Total other income (expense), net	$	14.5	$	(0.4)	$	17.4	$	(0.8)

Roll Forward of Restructuring Reserve Activity

Restructuring reserves for severance cost activity is as follows:

	Severance and Employee
	Benefit Costs
Balance at December 31, 2020	$	43.4
Adjustments	(9.2)
Payments	(12.4)
Balance at September 30, 2021	$	21.8