Business Segments - Narrative (Details) $ in Thousands				12 Months Ended
	Nov. 17, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 30, 2023 USD ($)	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)
Segment Reporting Information
Number of operating segments | segment				2
Number of reportable segments | segment				2
Proceeds from asset divestitures				$ 0	$ 7,706
Gain (loss) on asset divestitures		$ (1,009)	$ (2,065)	0	(3,074)
Net sales				530,765	543,744
Restructuring charges				1,456
Gain on sale of former joint venture facility				3,477	0
Accounts receivable, credit loss expense (reversal)				700
Cost of Sales
Segment Reporting Information
Restructuring charges				245
Selling, General and Administrative Expenses
Segment Reporting Information
Restructuring charges				1,211
Accounts receivable, credit loss expense (reversal)				365	1,912
Bridge Grid Deck Product | Sales
Segment Reporting Information
Contract with customer, liability, cumulative catch-up adjustment to revenue, change in estimate of transaction price					1,977
Bridge Grid Deck Product | Gross Profit
Segment Reporting Information
Contract with customer, liability, cumulative catch-up adjustment to revenue, change in estimate of transaction price					3,051
Infrastructure Solutions
Segment Reporting Information
Net sales				203,896	231,584
Rail, Technologies, and Services
Segment Reporting Information
Net sales				326,869	312,160
Operating Segments
Segment Reporting Information
Net sales				530,765	543,744
Operating Segments | Infrastructure Solutions
Segment Reporting Information
Proceeds from asset divestitures				1,300
Gain (loss) on asset divestitures				815
Net sales				203,896	231,584
Restructuring charges				113
Operating Segments | Rail, Technologies, and Services
Segment Reporting Information
Net sales				326,869	312,160
Restructuring charges				1,134
Accounts receivable, credit loss expense (reversal)					1,862
Restructuring costs					676
Operating Segments | Rail, Technologies, and Services | One Customer | Customer Concentration Risk
Segment Reporting Information
Net sales				71,800
Disposal Group, Not Discontinued Operations | Bridge Grid Deck Product
Segment Reporting Information
Net sales				$ 3,700	6,146
Loss on asset divestitures					1,403
Inventory write-down					474
Personnel expenses					667
Other exit costs					262
Disposal Group, Not Discontinued Operations | Bridge Grid Deck Product | Cost of Sales
Segment Reporting Information
Loss on asset divestitures					1,141
Disposal Group, Not Discontinued Operations | Bridge Grid Deck Product | Selling, General and Administrative Expenses
Segment Reporting Information
Loss on asset divestitures					$ 262
Cougar Mountain Precast, LLC
Segment Reporting Information
Consideration transferred to acquire operating assets	$ 1,644
Coatings and Measurement
Segment Reporting Information
Proceeds from asset divestitures			5,344
Rail Products Business Unit
Segment Reporting Information
Proceeds from asset divestitures		2,362
Gain (loss) on asset divestitures		$ (1,009)	$ (2,065)