2.2.0.25falsefalse40101 - Disclosure - Summary of Significant Accounting Policies (Projects with final estimated contract profit revisions whose impact exceeded $1 million) (Details)truefalseIn Thousands, unless otherwise specifiedfalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $Duration_1_1_2011_To_3_31_2011http://www.sec.gov/CIK0001130385duration2011-01-01T00:00:002011-03-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit16Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2falsefalseUSDfalsefalse1/1/2010 - 3/31/2010 USD ($) USD ($) / shares $Duration_1_1_2010_To_3_31_2010http://www.sec.gov/CIK0001130385duration2010-01-01T00:00:002010-03-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit16Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit13Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2true0fwlt_SummaryOfSignificantAccountingPoliciesAbstractfwltfalsenadurationSummary of Significant Accounting Policies [Abstract}.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringSummary of Significant Accounting Policies [Abstract}.falsefalseSummary of Significant Accounting Policies3false0fwlt_SeparateProjectsWithContractRevisionsfwltfalsenadurationNumber of separate projects that had final estimated contract profit revisions whose impact on accrued profit exceeded a...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse77falsefalsefalsefalsefalse2truefalsefalse1111falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerNumber of separate projects that had final estimated contract profit revisions whose impact on accrued profit exceeded a million.No authoritative reference available.falsefalseNumber of separate projects4false0fwlt_ContractProfitChangesfwltfalsecreditdurationThe current period impact on final estimated contract profit resulting from a change in estimated final contract revenues or...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-4600000-4600[1],[2]falsetruefalsefalsefalse2truefalsefalse1310000013100[1],[2]falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe current period impact on final estimated contract profit resulting from a change in estimated final contract revenues or costs relating to the revaluation of work performed on contracts in prior periods.No authoritative reference available.falsefalseNet (decrease)/increase in contract profit from the regular revaluation of final estimated contract profit revisions1Please refer to “Revenue Recognition on Long-Term Contracts” in Note 1 for further information regarding changes in our final estimated contract profit.2The changes in final estimated contract profit revisions during the fiscal three months ended March 31, 2011 included the impact of two out-of-period corrections for the reduction of final estimated profit totaling $7,800, which included final estimated profit reductions in our Global E&C Group and our Global Power Group of $3,200 and $4,600, respectively. The corrections were recorded in the current period as they were not material to previously issued financial statements, nor are they expected to be material to the full year 2011 financial statements.23Summary of Significant Accounting Policies (Projects with final estimated contract profit revisions whose impact exceeded $1 million) (Details) (USD $)ThousandsUnKnownUnKnownUnKnowntruetrue