Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net earnings	$ 107.7	$ 46.0	$ (28.1)
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	98.6	103.3	105.0
Equity-based compensation expense	9.9	12.7	9.1
Deferred Income Taxes and Tax Credits	(14.9)	(7.9)	(9.7)
Defined benefit pension and other postretirement employee benefits	(2.0)	3.0	7.2
Amortization of deferred debt costs and debt retirement	4.4	2.0	2.8
Loss on sale or impairment associated with assets	2.1	6.1	35.7
(Increase) decrease in accounts receivable	(1.3)	(16.9)	(5.3)
(Increase) decrease in inventories	4.0	(46.3)	(20.2)
(Increase) decrease in other current assets	0.8	(2.4)	(1.7)
Increase (Decrease) in Accounts Payable and Accrued Liabilities	(21.3)	49.2	1.9
Other, net	2.6	1.5	(0.2)
Net cash flows provided by operating activities	190.7	150.2	96.4
CASH FLOWS FROM INVESTING ACTIVITIES
Payments to Acquire Property, Plant, and Equipment	(73.7)	(33.5)	(38.4)
Net proceeds from divested assets	0.0	0.0	13.3
Net cash flows used in investing activities	(73.7)	(33.5)	(25.1)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings on long-term debt	222.0	0.0	0.0
Repayments of long-term debt	(325.6)	(80.9)	(81.0)
Payment, Tax Withholding, Share-based Payment Arrangement	(4.7)	(2.5)	(1.7)
Payments for Repurchase of Common Stock	(17.9)	(5.0)	0.0
Payments for debt issuance costs	(3.1)	(0.9)	0.0
Other, net	0.0	0.8	0.7
Net cash flows used in financing activities	(129.4)	(88.6)	(82.0)
Increase (decrease) in cash, cash equivalents and restricted cash	(12.4)	28.2	(10.7)
Cash, cash equivalents and restricted cash at beginning of period	42.0	54.4	26.2
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest, net of amounts capitalized	37.8	33.0	36.0
Cash (received) paid for income taxes	16.6	43.0	(7.7)
Capital Expenditures Incurred but Not yet Paid	$ 13.0	$ 15.7	$ 11.0