Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net earnings	$ 77.1	$ (5.6)	$ (143.8)
Adjustments to reconcile net earnings to net cash provided by operating activities:
Goodwill impairment	0.0	0.0	195.1
Depreciation and amortization	111.0	115.6	101.9
Equity-based compensation expense	10.5	4.1	3.3
Deferred Income Taxes and Tax Credits	33.5	(0.3)	7.1
Pension and other postretirement employee benefits	3.8	1.4	(0.6)
Debt retirement costs	5.9	2.7	0.0
Gain on divested assets, net	(1.4)	0.0	(25.5)
(Increase) decrease in accounts receivable	6.1	(18.0)	6.6
(Increase) decrease in inventory	18.1	(21.2)	(8.1)
(Increase) decrease in other current assets	(11.2)	(0.8)	6.4
Increase (Decrease) in Accounts Payable, Trade	(16.5)	(53.9)	18.9
Increase (Decrease) in Employee Related Liabilities	(2.5)	4.8	(0.9)
Increase in other accrued liabilities	7.0	20.7	7.3
Other, net	5.6	6.1	1.2
Net cash flows provided by operating activities	247.0	55.6	168.9
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to property, plant and equipment	(39.6)	(140.1)	(295.7)
Net proceeds from divested assets	0.0	0.0	70.9
Other, net	0.0	0.0	0.8
Net cash flows used in investing activities	(39.6)	(140.1)	(224.0)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings on short-term debt	108.5	549.3	630.8
Repayments of borrowings on short-term debt	(122.0)	(657.7)	(565.0)
Proceeds from long-term debt, net	275.0	296.1	0.0
Repayment of long-term debt	(449.4)	(103.0)	0.0
Payments for debt issuance costs	(4.4)	(2.3)	(2.1)
Other, net	(0.7)	(0.4)	(0.4)
Net cash flows (used in) provided by financing activities	(192.9)	82.0	63.3
Increase (decrease) in cash, cash equivalents and restricted cash	14.4	(2.5)	8.2
Cash, cash equivalents and restricted cash at beginning of period	36.9	22.4	24.9
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest, net of amounts capitalized	45.0	38.4	26.1
Income Taxes Paid, Net	$ (7.9)	$ 3.1	$ (10.6)