Discontinued Operations and Disposal Groups (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash Provided by (Used in) Investing Activities, Discontinued Operations	$ 0.0	$ (1.1)
Loss on sale of discontinued operations, net of benefit for income taxes of $0.4 and $—	(1.1)	0.0
Discontinued Operation, Tax Effect of Discontinued Operation	(2.0)	2.3
(Income) loss from discontinued operations, net of income taxes	(6.9)	6.3
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 income taxes		(0.4)
Sale of Highway Products
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash Provided by (Used in) Investing Activities, Discontinued Operations			$ 364.7
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	(1.5)
Loss on sale of discontinued operations, net of benefit for income taxes of $0.4 and $—	(1.1)
Disposal Group, Including Discontinued Operation, Revenue	0.0	68.1
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	0.0	49.5
Disposal Group, Including Discontinued Operation, General and Administrative Expense	8.9	10.0
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	(8.9)	8.6
Discontinued Operation, Tax Effect of Discontinued Operation	(2.0)	1.9
(Income) loss from discontinued operations, net of income taxes	$ (6.9)	$ 6.7