Investments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified
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12 Months Ended |
Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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Schedule of Equity Method Investments [Line Items] |
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Equity Investments |
$ 5,824us-gaap_EquityMethodInvestments |
$ 5,090us-gaap_EquityMethodInvestments |
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Equity in Income/(Loss) of Nonconsolidated Investment |
1,282us-gaap_IncomeLossFromEquityMethodInvestments |
1,316us-gaap_IncomeLossFromEquityMethodInvestments |
837us-gaap_IncomeLossFromEquityMethodInvestments |
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital |
630us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital |
558us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital |
0us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital |
LB Pipe JV [Member] |
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Schedule of Equity Method Investments [Line Items] |
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Equity Investments |
5,746us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
5,090us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
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Equity Method Investment, Ownership Percentage |
45.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
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Equity Method Investment, Description of Principal Activities |
The Company is a member of a joint venture, L B Pipe and Coupling Products, LLC (LB Pipe JV) in which it maintains a 45% ownership interest. The LB Pipe JV manufactures, markets, and sells various precision coupling products for the energy, utility, and construction markets and is scheduled to terminate on June 30, 2019 |
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Equity in Income/(Loss) of Nonconsolidated Investment |
1,286us-gaap_IncomeLossFromEquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
1,316us-gaap_IncomeLossFromEquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
837us-gaap_IncomeLossFromEquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital |
630us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
558us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
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Capital Leases, Net Investment in Direct Financing Leases |
1,117us-gaap_CapitalLeasesNetInvestmentInDirectFinancingLeases / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
1,224us-gaap_CapitalLeasesNetInvestmentInDirectFinancingLeases / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = fstr_LbPipeJvMember |
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Other Investments [Member] |
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Schedule of Equity Method Investments [Line Items] |
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Equity Investments |
78us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_OtherInvestmentsMember |
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Capital Leased Land [Member] |
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Schedule of Equity Method Investments [Line Items] |
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Area of Land |
5us-gaap_AreaOfLand / us-gaap_PropertyPlantAndEquipmentByTypeAxis = fstr_CapitalLeasedLandMember |
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Capital Leased Assets, Number of Units |
2us-gaap_CapitalLeasedAssetsNumberOfUnits / us-gaap_PropertyPlantAndEquipmentByTypeAxis = fstr_CapitalLeasedLandMember |
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Capital Lease Length Of Lease Term |
9 years 6 months |
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Capital Lease Length Of Renewal Term |
5 years 6 months |
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Capital Leases, Monthly Rent |
17fstr_CapitalLeasesMonthlyRent / us-gaap_PropertyPlantAndEquipmentByTypeAxis = fstr_CapitalLeasedLandMember |
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Capital Leases Balloon Payment In Direct Financing Leases |
$ 488fstr_CapitalLeasesBalloonPaymentInDirectFinancingLeases / us-gaap_PropertyPlantAndEquipmentByTypeAxis = fstr_CapitalLeasedLandMember |
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Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member] |
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Schedule of Equity Method Investments [Line Items] |
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Variable Interest Entity, Methodology for Determining Whether Entity is Primary Beneficiary |
Under applicable guidance for variable interest entities in ASC 810, "Consolidation," the Company determined that the LB Pipe JV is a variable interest entity. The Company concluded that it is not the primary beneficiary of the variable interest entity, as the Company does not have a controlling financial interest and does not have the power to direct the activities that most significantly impact the economic performance of the LB Pipe JV. Accordingly, the Company concluded that the equity method of accounting remains appropriate |
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