STATEMENTS OF CONSOLIDATED CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income (loss)	$ 39.6	$ (3.2)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation of property, plant and equipment	75.7	72.5
Amortization of definite-lived intangible assets	4.2	7.9
Amortization of debt premium and debt issuance costs	1.6	1.6
Deferred income taxes	6.3	(3.5)
Non-cash equity compensation	11.8	11.1
Non-cash asset impairment charge		3.2
Gain on disposition of property, plant and equipment	(14.0)	(6.3)
Changes in operating assets and liabilities:
Trade and other receivables	11.7	17.3
Contract assets	6.0	12.2
Inventories	36.8	(133.5)
Prepaid expenses and other current assets	(6.8)	(4.3)
Accounts payable	(53.9)	(40.6)
Accrued liabilities	10.6	8.3
Long-term assets and liabilities, net	8.0	(1.3)
Net cash provided by (used in) operating activities	137.6	(58.6)
Cash flows from investing activities:
Capital expenditures	(120.0)	(82.4)
Purchase of equity securities	(0.3)	(0.3)
Proceeds from sale of equity securities	0.1
Proceeds from disposition of property, plant and equipment	15.2	11.0
Net cash used in investing activities	(105.0)	(71.7)
Cash flows from financing activities:
Borrowings under the Revolving Credit Facility	215.1
Repayment of borrowings under the Revolving Credit Facility	(215.1)
Cash paid for debt issuance costs		(1.8)
Repayment of finance lease	(1.7)	(1.0)
Cancellation of shares to cover tax withholdings upon common shares issued	(1.8)	(2.8)
Cash dividends and dividend equivalents paid	(37.7)	(37.6)
Net cash used in financing activities	(41.2)	(43.2)
Net decrease in cash, cash equivalents and restricted cash during the period	(8.6)	(173.5)
Cash, cash equivalents and restricted cash at beginning of period	71.3	317.0
Cash, cash equivalents and restricted cash at end of period	$ 62.7	$ 143.5