CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities
Net income	$ 452.0	$ 1,326.9	$ 1,296.7
Adjustments to reconcile net income to net cash and cash equivalents provided by (used for) operating activities:
Depreciation and amortization	533.4	598.8	582.5
Gains on disposition of property, plant and equipment	(27.0)	(13.0)	(1.4)
Stock-based compensation	18.6	14.1	8.3
Loss on debt extinguishment	0.0	0.0	152.2
Write-off of equipment and facility included in restructuring charges	17.7	0.0	0.0
Deferred income taxes	(55.6)	(32.4)	(42.7)
Qualified pension plan contributions	(1.1)	(1.3)	(1.1)
Qualified pension plan income	21.0	33.1	27.8
Change in assets and liabilities:
Receivables	65.4	160.8	(360.0)
Income taxes receivable/payable	45.8	(2.9)	105.1
Inventories	94.4	(86.3)	(206.0)
Other current assets	(3.1)	15.9	(22.3)
Accounts payable and accrued liabilities	(133.9)	(22.3)	240.1
Other assets	(23.4)	(2.6)	(13.3)
Other noncurrent liabilities	15.8	(0.7)	26.2
Other operating activities	(3.7)	0.0	4.5
Net operating activities	974.3	1,921.9	1,741.0
Investing Activities
Capital expenditures	(236.0)	(236.9)	(200.6)
Business acquired in purchase transaction, net of cash acquired	63.9	0.0	0.0
Payments under other long-term supply contracts	(64.5)	(37.7)	0.0
Proceeds from disposition of property, plant and equipment	28.8	14.9	3.2
Other investing activities	(5.2)	0.0	0.0
Net investing activities	(340.8)	(259.7)	(197.4)
Long-term debt:
Borrowings	707.7	415.0	540.0
Repayments	621.8	616.1	1,643.1
Debt early redemption premiums	0.0	0.0	(137.7)
Common stock repurchased and retired	(711.3)	(1,350.7)	(251.9)
Stock options exercised	25.4	25.7	72.4
Dividends paid	(101.0)	(116.2)	(127.8)
Debt issuance costs	0.0	(4.4)	(3.9)
Contributions received from noncontrolling interests	44.1	0.0	0.0
Net financing activities	(656.9)	(1,646.7)	(1,552.0)
Effect of exchange rate changes on cash and cash equivalents	(0.3)	(2.0)	(0.8)
Net (decrease) increase in cash and cash equivalents	(23.7)	13.5	(9.2)
Cash and cash equivalents, beginning of year	194.0	180.5	189.7
Cash and cash equivalents, end of year	170.3	194.0	180.5
Cash paid for interest and income taxes:
Interest, net	176.8	141.7	345.2
Income taxes, net of refunds	$ 111.7	$ 356.6	$ 169.6