XML 126 R111.htm IDEA: XBRL DOCUMENT
v3.24.3

Commitments and Contingent Liabilities - Narrative (Details) $ in Thousands |  | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Mar. 13, 2019 USD ($) | Dec. 31, 2023 USD ($) party | Dec. 31, 2018 USD ($) | Dec. 31, 2022 USD ($) | Sep. 30, 2021 USD ($) | Mar. 26, 2020 party | Jun. 05, 2017 company
Product Liability Contingency |  |  |  |  |  |  |
Current portion of accrued settlement |  | $ 8,000 |  | $ 8,000 |  |  |
Long-term portion of accrued settlement (Note 18) |  | 0 |  | $ 8,000 |  |  |
Number of companies receiving general notice letter | company |  |  |  |  |  |  | 140
Present value or proposed remedial work |  | 1,100,000 |  |  |  |  |
Undiscovered remedial work |  | $ 1,700,000 |  |  |  |  |
Remedial work anticipated clean up period |  | 13 years |  |  |  |  |
Number of potentially responsible parties included in agreement | party |  | 100 |  |  |  |  |
Number of parties required to perform remedial design work | party |  |  |  |  |  | 2 |
UPRR |  |  |  |  |  |  |
Product Liability Contingency |  |  |  |  |  |  |
Purchase commitment | $ 48,000 |  |  |  |  |  |
Annual commitment amount | 8,000 |  |  |  | $ 6,000 |  |
UPRR |  |  |  |  |  |  |
Product Liability Contingency |  |  |  |  |  |  |
Litigation settlement amount | 50,000 |  |  |  |  |  |
Litigation settlement amount, current | 2,000 |  |  |  |  |  |
Litigation settlement amount, non-current | $ 48,000 |  |  |  |  |  |
Litigation settlement installment payment term | 6 years |  |  |  |  |  |
Estimated litigation liability, payment due year one |  | $ 8,000 |  |  |  |  |
Amounts reclassified to accrued settlement | $ 6,600 |  |  |  |  |  |
Legal fees |  |  | $ 43,400 |  |  |  |

X
- Definition Accrued Legal Settlement, Current + References No definition available. + Details
Name: | fstr_AccruedLegalSettlementCurrent
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Accrued Legal Settlement, Non-Current + References No definition available. + Details
Name: | fstr_AccruedLegalSettlementNonCurrent
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Estimated Litigation Liability, Amount Awarded to Other Party, Payment Due Year One + References No definition available. + Details
Name: | fstr_EstimatedLitigationLiabilityAmountAwardedToOtherPartyPaymentDueYearOne
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Litigation Settlement, Amount Awarded to Other Party, Current + References No definition available. + Details
Name: | fstr_LitigationSettlementAmountAwardedToOtherPartyCurrent
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Litigation Settlement, Amount Awarded to Other Party, Non-Current + References No definition available. + Details
Name: | fstr_LitigationSettlementAmountAwardedToOtherPartyNonCurrent
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Litigation Settlement Installment Payment Term + References No definition available. + Details
Name: | fstr_LitigationSettlementInstallmentPaymentTerm
Namespace Prefix: | fstr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Long-term Purchase Commitment, Annual Commitment Amount + References No definition available. + Details
Name: | fstr_LongtermPurchaseCommitmentAnnualCommitmentAmount
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number Of Companies Receiving General Notice Letter + References No definition available. + Details
Name: | fstr_NumberOfCompaniesReceivingGeneralNoticeLetter
Namespace Prefix: | fstr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Parties Required to Perform Remedial Work + References No definition available. + Details
Name: | fstr_NumberOfPartiesRequiredToPerformRemedialWork
Namespace Prefix: | fstr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Potentially Responsible Parties Included in Agreement + References No definition available. + Details
Name: | fstr_NumberOfPotentiallyResponsiblePartiesIncludedInAgreement
Namespace Prefix: | fstr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Present Value of Proposed Remedial Work + References No definition available. + Details
Name: | fstr_PresentValueOfProposedRemedialWork
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Remedial Work Anticipated Clean Up Period + References No definition available. + Details
Name: | fstr_RemedialWorkAnticipatedCleanUpPeriod
Namespace Prefix: | fstr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Standard Product Warranty Accrual, Reclassification + References No definition available. + Details
Name: | fstr_StandardProductWarrantyAccrualReclassification
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Undiscovered Remedial Work + References No definition available. + Details
Name: | fstr_UndiscoveredRemedialWork
Namespace Prefix: | fstr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_LegalFees
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount awarded to other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The minimum amount the entity agreed to spend under the long-term purchase commitment. + References No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480102/450-20-S99-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-4 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483076/450-20-50-9 + Details
Name: | us-gaap_ProductLiabilityContingencyLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=fstr_UPRRMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=fstr_UPRRMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |