CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Statement of Comprehensive Income [Abstract]
Net income		$ 4,325	$ 35,898	$ 5,047	$ 43,120
Other comprehensive income, net of tax:
Foreign currency translation adjustment		(513)	1,376	1,529	(590)
Unrealized loss on cash flow hedges, net of tax expense of $0		(44)	(698)	(351)	(778)
Reclassification of pension liability adjustments to earnings, net of tax expense of $0, $5, $0, and $12, respectively*	[1]	0	24	0	75
Total comprehensive income		3,768	36,600	6,225	41,827
Less comprehensive loss attributable to noncontrolling interest:
Net loss attributable to noncontrolling interest		(29)	(7)	(82)	(68)
Foreign currency translation adjustment		23	18	177	(71)
Amounts attributable to noncontrolling interest		(6)	11	95	(139)
Comprehensive income attributable to L.B. Foster Company		$ 3,774	$ 36,589	$ 6,130	$ 41,966

[1] Reclassifications out of “Accumulated other comprehensive loss” for pension obligations are charged to “Selling and administrative expenses” within the Condensed Consolidated Statements of Operations.