CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities:
Net income	$ 226.6	$ 295.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	72.7	64.3
Amortization	1.8	1.4
Stock-based compensation	9.3	16.0
Loss on disposal of plant	0.0	11.6
Asset impairments	0.9	3.4
Other non-cash items, net	(7.6)	(12.4)
Changes in assets and liabilities	(20.5)	(72.1)
Net cash provided by operating activities	283.2	307.3
Cash flows from investing activities:
Capital expenditures	(190.8)	(157.5)
Other, net	(1.0)	(6.7)
Net cash used in investing activities	(191.8)	(164.2)
Cash flows from financing activities:
Borrowings of long-term debt	35.0	0.0
Repayments of long-term debt	(36.1)	(1.1)
Principal repayments on finance leases	(22.9)	0.0
Dividend payments	(29.3)	(28.2)
Proceeds from stock-based compensation awards	19.9	24.0
Employee stock purchase plan contributions	3.7	3.5
Shares purchased under share repurchase programs	(454.1)	(233.5)
Shares repurchased for employee tax withholdings	(5.5)	(12.5)
Net cash used in financing activities	(489.3)	(247.8)
Effect of exchange rates on cash	(9.8)	6.7
Net decrease in cash and cash equivalents	(407.7)	(98.0)
Cash, including cash equivalents at beginning of period	853.9	894.3
Cash, including cash equivalents at end of period	$ 446.2	$ 796.3