Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net earnings (loss)	$ 183.2	$ (99.1)	$ 214.5
Adjustments to reconcile net earnings (loss) to net cash provided by operating activities:
Depreciation and amortization	96.5	84.0	72.1
Loss on disposal of discontinued operations	0.4	16.4	31.2
Write-off of debt refinancing fees	0.0	0.0	2.7
Gain related to sale of fixed and intangible assets	0.0	(21.0)	0.0
Deferred income taxes	8.7	(89.3)	14.0
Share-based compensation	11.3	6.8	9.5
Equity (earnings) from joint venture	(87.7)	(64.0)	(96.6)
U.S. pension cost (credit)	0.1	367.7	(7.5)
(Gain) loss related to change in fair value of contingent consideration	(4.1)	0.1	0.0
Other non-cash adjustments, net	0.9	0.9	2.5
Changes in operating assets and liabilities:
Receivables	(30.9)	12.7	(1.1)
Inventories	(10.6)	(7.7)	(7.2)
Accounts payable and accrued expenses	38.6	(11.9)	(19.9)
Income taxes receivable and payable, net	(2.0)	35.2	(8.4)
Other assets and liabilities	(17.2)	(12.0)	(23.1)
Net cash provided by operating activities	187.2	218.8	182.7
Cash flows from investing activities:
Purchases of property, plant and equipment	(79.8)	(55.4)	(71.3)
Return of investment from joint venture	78.3	81.5	85.2
Cash paid for acquisitions, net of cash acquired	(0.7)	(164.6)	(56.4)
Proceeds from the sale of assets	0.1	21.7	0.0
Payments of proceeds from Knauf to investment in joint venture	0.0	(25.9)	0.0
Payments to Knauf upon disposal of discontinued operations	(11.8)	(6.4)	(47.9)
Proceeds from company-owned life insurance, net	0.0	8.0	1.3
Net cash (used for) investing activities	(13.9)	(141.1)	(89.1)
Cash flows from financing activities:
Proceeds from short-term debt	0.0	30.0	0.0
Payments of short-term debt	0.0	(30.0)	0.0
Proceeds from revolving credit facility	95.0	290.0	185.0
Payments of revolving credit facility	(155.0)	(180.0)	(70.0)
Proceeds from long-term debt	0.0	0.0	500.0
Payments of long-term debt	(25.0)	(6.3)	(825.4)
Financing costs	0.0	0.0	(2.9)
Dividends paid	(41.4)	(39.2)	(35.6)
Payments from share-based compensation plans, net of tax	(3.6)	(4.8)	(4.7)
Payments for finance leases	2.1	1.8	0.0
Payments for treasury stock acquired	(80.0)	(44.4)	(131.3)
Net cash (used for) provided by financing activities	(212.1)	13.5	(384.9)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.4	0.9
Net (decrease) increase in cash and cash equivalents	(38.8)	91.6	(290.4)
Cash and cash equivalents at beginning of year of discontinued operations	0.0	0.0	10.0
Cash and cash equivalents at beginning of year of continuing operations	136.9	45.3	325.7
Cash and cash equivalents at end of period	98.1	136.9	45.3
Supplemental Cash Flow Disclosures:
Interest paid	21.5	24.1	33.1
Income tax payments, net	52.5	10.9	58.4
Amounts in accounts payable for capital expenditures	$ 0.3	$ 1.0	$ 1.9