Note 2. Acquisitions and Discontinued Operations - Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Tax Effect of Discontinued Operation	$ (3.6)	$ (1.1)	$ 3.5
Income (loss) from discontinued operations, net of provision (benefit) for income taxes of $(3.6), $(1.1), and $3.5	(13.4)	(20.3)	11.1
Gain (loss) on sale of discontinued operations, net of provision (benefit) for income taxes of $—, $(1.4), and $51.9	0.0	(5.7)	131.4
Amounts reclassified to discontinued operations, net of tax	0.0	1.3	0.0
Sale of Highway Products
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	0.0	0.0	296.5
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	0.0	0.0	216.6
Disposal Group, Including Discontinued Operation, General and Administrative Expense	17.0	21.4	65.3
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	(17.0)	(21.4)	14.6
Discontinued Operation, Tax Effect of Discontinued Operation	(3.6)	(1.1)	2.7
Income (loss) from discontinued operations, net of provision (benefit) for income taxes of $(3.6), $(1.1), and $3.5	(13.4)	(20.3)	11.9
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax		(5.8)	183.3
Gain (loss) on sale of discontinued operations, net of provision (benefit) for income taxes of $—, $(1.4), and $51.9		(4.4)
Sale of Highway Products | Proceeds from (Payments to) related to the Sale of Discontinued Operations, Net of Cash Divested
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds (Payments) Related to Sale of Discontinued Operations	$ 0.0	$ 2.7	(364.7)
Spin-Off of Arcosa
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest			$ 0.8