Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net income	$ 132.1	$ 105.7	$ 126.3
Reconciliation to net cash provided by operating activities:
Depreciation and amortization	124.0	124.8	126.2
Amortization of deferred financing costs and debt discount	0.4	0.6	0.7
Deferred income taxes	(16.7)	(32.7)	(3.1)
Equity in earnings from affiliated companies	0.0	(8.1)	(8.1)
Stock-based compensation	22.2	20.9	20.0
Restructuring expenses, net of payments	0.0	(4.4)	(0.7)
Pension Settlement	0.0	70.5	0.0
Gain on sale of assets	0.0	(0.8)	(19.4)
Impairment of assets	28.9	3.1	1.6
Loss (gain) on sale of investments	0.0	3.0	(0.3)
Changes in assets and liabilities:
Decrease (increase) in accounts receivable	10.7	(8.9)	(62.8)
Increase in inventories	(34.0)	(8.9)	(82.4)
(Increase) decrease in prepaid expenses and other current assets	(6.7)	2.6	(8.3)
Increase (decrease) in accounts payable/accrued liabilities	29.2	(12.2)	80.8
Other – net	(0.2)	1.9	2.6
Net cash provided by operating activities	289.9	257.1	173.1
Cash flows from investing activities
Capital expenditures	(87.0)	(108.2)	(76.3)
Proceeds from sale of assets	0.0	10.3	21.2
Proceeds from sale of investments	0.0	47.2	0.5
Net cash used for investing activities	(87.0)	(50.7)	(54.6)
Cash flows from financing activities
Repayment of finance lease obligation and other debt, net	0.3	(0.2)	(0.6)
Issuance costs related to senior credit facility	0.0	(2.5)	0.0
Dividends paid	(49.3)	(42.2)	(33.7)
Repurchase of stock	(252.2)	(30.1)	0.0
Activity under stock plans	(0.5)	7.4	4.3
Net cash used for financing activities	(301.7)	(92.6)	(130.0)
Effect of exchange rate changes on cash and cash equivalents	(2.8)	1.2	(4.2)
Net (decrease) increase in cash and cash equivalents	(101.6)	115.0	(15.7)
Cash and cash equivalents at beginning of period	227.0	112.0	127.7
Cash and cash equivalents at end of period	125.4	227.0	112.0
Supplemental data:
Interest, net of capitalized interest	33.5	34.6	35.4
Income Taxes	42.2	59.1	35.9
Accrual basis additions to property, plant and equipment	81.1	121.6	69.8
Senior Unsecured Credit Facility Two Thousand Twenty Eight [Member]
Cash flows from financing activities
Borrowing from senior unsecured credit facility	160.0	98.0	0.0
Repayment of senior unsecured credit facility	(160.0)	(98.0)	0.0
Senior Unsecured Credit Facility Two Thousand Twenty Four [Member]
Cash flows from financing activities
Borrowing from senior unsecured credit facility	0.0	65.0	50.0
Repayment of senior unsecured credit facility	$ 0.0	$ (90.0)	$ (150.0)