CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Statement of Comprehensive Income [Abstract]
Net (loss) income		$ (2,117)	$ 4,405
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment		103	(1,497)
Unrealized (loss) gain on cash flow hedges, net of tax expense of $0		(266)	106
Reclassification of pension liability adjustments to earnings, net of tax expense of $0 and $4, respectively	[1]	0	25
Total comprehensive (loss) income		(2,280)	3,039
Less comprehensive loss attributable to noncontrolling interest:
Net loss attributable to noncontrolling interest		(7)	(31)
Foreign currency translation adjustment		116	(17)
Amounts attributable to noncontrolling interest		109	(48)
Comprehensive (loss) income attributable to L.B. Foster Company		$ (2,389)	$ 3,087

[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.