STATEMENTS OF CONSOLIDATED CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income	$ 39.7	$ 39.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, plant and equipment	83.4	75.7
Amortization of definite-lived intangible assets	3.4	4.2
Amortization of debt premium and debt issuance costs	1.8	1.6
Amortization of cloud computing implementation costs	0.9	0.9
Deferred income taxes	8.5	6.3
LIFO valuation inventory expense (benefit)	8.8	(1.5)
Non-cash equity compensation	11.7	11.8
Non-cash asset impairment charge	3.6
Non-cash unrealized loss (gain) on derivative positions	2.2	(0.2)
Gain on disposition of property, plant and equipment	(3.7)	(14.0)
Bad debt expense	0.3
Non-cash postretirement defined benefit plan cost	6.8	9.7
Changes in operating assets and liabilities:
Trade and other receivables	(33.7)	11.7
Contract assets	(3.5)	6.0
Inventories (excluding LIFO adjustments)	(8.7)	38.3
Prepaid expenses and other current assets	(5.6)	(6.7)
Accounts payable	17.5	(53.9)
Accrued liabilities	(11.6)	10.6
Annual variable cash contributions to Salaried VEBA	(1.1)
Long-term assets and liabilities, net	3.0	(2.5)
Net cash provided by operating activities	123.7	137.6
Cash flows from investing activities:
Capital expenditures	(124.8)	(120.0)
Purchase of equity securities	(0.1)	(0.3)
Proceeds from sale of equity securities	0.3	0.1
Proceeds from disposition of property, plant and equipment	6.0	15.2
Net cash used in investing activities	(118.6)	(105.0)
Cash flows from financing activities:
Borrowings under the Revolving Credit Facility		215.1
Repayment of borrowings under the Revolving Credit Facility		(215.1)
Repayment of finance lease	(2.0)	(1.7)
Cancellation of shares to cover tax withholdings upon common shares issued	(1.8)	(1.8)
Cash dividends and dividend equivalents paid	(38.0)	(37.7)
Net cash used in financing activities	(41.8)	(41.2)
Net decrease in cash, cash equivalents and restricted cash during the period	(36.7)	(8.6)
Cash, cash equivalents and restricted cash at beginning of period	100.7	71.3
Cash, cash equivalents and restricted cash at end of period	$ 64.0	$ 62.7