Supplemental Balance Sheet Information (Tables)

12 Months Ended

Dec. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Supplemental Balance Sheet Information

2. Supplemental Balance Sheet Information

	As of December 31,
	2020			2019
	(In millions of dollars)
Cash and Cash Equivalents
Cash and money market funds	$	780.3		$	28.2
Commercial paper		—			236.1
Total	$	780.3		$	264.3
Trade Receivables, net
Billed trade receivables	$	113.6		$	168.5
Allowance for doubtful receivables		(0.8	)		(1.4	)
Trade receivables, net	$	112.8		$	167.1
Inventories
Finished products	$	37.2		$	42.6
Work-in-process		46.0			63.5
Raw materials		62.3			65.0
Operating supplies		6.5			6.5
Total	$	152.0		$	177.6
Property, Plant and Equipment, net
Land and improvements	$	21.5		$	21.4
Buildings and leasehold improvements		117.2			104.5
Machinery and equipment		847.4			813.5
Construction in progress1		37.8			33.2
Property, plant and equipment, gross		1,023.9			972.6
Accumulated depreciation and amortization		(398.4	)		(352.2	)
Assets held for sale		1.7			1.6
Property, plant and equipment, net	$	627.2		$	622.0
Other Accrued Liabilities
Uncleared cash disbursements	$	2.1		$	4.2
Accrued income taxes and other taxes payable		5.2			6.2
Accrued annual contribution to VEBAs – Note 5		1.7			2.9
Accrued interest		11.6			2.3
Short-term environmental accrual – Note 10		3.7			5.5
Other – Note 3 and Note 8		17.1			22.9
Total	$	41.4		$	44.0
Long-Term Liabilities
Workers' compensation accruals	$	30.6		$	27.7
Long-term environmental accrual – Note 10		15.1			11.5
Other long-term liabilities		32.9			27.8
Total	$	78.6		$	67.0

¹ Based on market conditions during the year ended December 31, 2020, we temporarily idled projects within Construction in progress totaling $20.0 million as of December 31, 2020, all of which are expected to resume at a future date.