CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities:
Net income	$ 56.6	$ 116.6	$ 108.1
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	51.1	45.9	43.3
Equity compensation expense	14.3	11.8	17.0
Deferred income taxes	(3.6)	(20.6)	(3.2)
Equity in undistributed income of unconsolidated joint ventures	(1.8)	(4.4)	(7.0)
Dividends received from unconsolidated joint ventures	4.3	4.7	5.0
Gain on sale of business	(0.7)	0.0	0.0
(Gain) loss on sale or disposal of property, plant and equipment	(2.6)	0.5	(0.9)
Impairment charges	0.0	65.1	0.5
UTIS fire fixed asset and inventory write-offs	0.0	0.2	1.9
Other non-cash charges (benefits), net	0.6	0.2	(0.5)
Changes in assets and liabilities:
Accounts receivable	(10.8)	(32.3)	(26.2)
Proceeds from insurance related to operations	25.6	1.2	0.4
Contract assets	(5.9)	(3.9)	(10.0)
Inventories, net	28.3	(51.6)	(34.4)
Other current assets	4.2	(6.3)	1.7
Accounts payable and other accrued expenses	(26.6)	(8.8)	36.5
Other, net	(1.6)	11.2	(7.8)
Net cash provided by operating activities	131.4	129.5	124.4
Investing Activities:
Acquisition of business, net of cash received	0.0	(3.6)	(168.2)
Disposition of business	1.7	0.0	0.0
Capital expenditures	(57.0)	(116.8)	(71.1)
Proceeds from the sale of property, plant and equipment, net	5.6	0.0	0.7
Proceeds from insurance claims	1.8	7.3	0.0
Net cash used in investing activities	(47.9)	(113.1)	(238.6)
Financing Activities:
Proceeds from borrowings under revolving credit facility	0.0	100.0	190.0
Repayment of debt principal and finance lease obligations	(185.4)	(75.3)	(29.6)
Line of credit issuance costs	(1.7)	0.0	0.0
Payments of taxes related to net share settlement of equity awards	(3.2)	(10.8)	(2.9)
Proceeds from issuance of shares to employee stock purchase plan	0.0	1.0	1.5
Share repurchases	0.0	(25.0)	0.0
Net cash (used in) provided by financing activities	(190.3)	(10.1)	159.0
Effect of exchange rate fluctuations on cash	2.6	(2.7)	(4.3)
Net increase (decrease) in cash and cash equivalents	(104.2)	3.6	40.5
Cash and cash equivalents at beginning of period	235.9	232.3	191.8
Cash and cash equivalents at end of period	131.7	235.9	232.3
Supplemental Disclosures:
Accrued capital additions	5.9	6.7	10.9
Cash paid during the year for:
Interest, net of amounts capitalized	10.4	9.7	2.4
Income taxes, net of refunds	$ 6.9	$ 60.8	$ 33.8