Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income from continuing operations		$ 3,471	$ 25,823
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment		(920)	1,500
Unrealized gain (loss) on cash flow hedges, net of tax expense (benefit) of $44 and $(277), respectively		131	(809)
Cash flow hedges reclassified to earnings, net of tax expense of $235 and $197, respectively		703	273
Pension and post-retirement benefit plans benefit (expense), net of tax expense (benefit) of $422 and $(325), respectively		1,436	(1,070)
Reclassification of pension liability adjustments to earnings, net of tax expense of $19 and $9, respectively*	[1]	55	21
Total comprehensive income from continuing operations		4,876	25,738
Less comprehensive loss attributable to noncontrolling interest:
Net loss attributable to noncontrolling interest		(83)	0
Foreign currency translation adjustment		(18)	0
Amounts attributable to noncontrolling interest		(101)	0
Comprehensive income from continuing operations attributable to L.B. Foster Company		$ 4,977	$ 25,738

[1] Reclassifications out of Accumulated other comprehensive loss for pension obligations are reflected in Selling and administrative expense.