3.8.0.1 html 132 300 1 true 39 0 false 9 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - Consolidated Balance Sheets (Unaudited) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/StatementConsolidatedBalanceSheetsUnaudited Consolidated Balance Sheets (Unaudited) Statements 2 false false R3.htm 100020 - Statement - Consolidated Balance Sheets (Unaudited) (Parenthetical) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/StatementConsolidatedBalanceSheetsUnauditedParenthetical Consolidated Balance Sheets (Unaudited) (Parenthetical) Statements 3 false false R4.htm 100030 - Statement - Consolidated Statements of Operations (Unaudited) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/StatementConsolidatedStatementsOfOperationsUnaudited Consolidated Statements of Operations (Unaudited) Statements 4 false false R5.htm 100040 - Statement - Consolidated Statements of Operations (Unaudited) (Parenthetical) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/StatementConsolidatedStatementsOfOperationsUnauditedParenthetical Consolidated Statements of Operations (Unaudited) (Parenthetical) Statements 5 false false R6.htm 100050 - Statement - Statement of Comprehensive Loss Statement Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/StatementStatementOfComprehensiveLossStatement Statement of Comprehensive Loss Statement Statements 6 false false R7.htm 100060 - Statement - Consolidated Statements of Cash Flows (Unaudited) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsUnaudited Consolidated Statements of Cash Flows (Unaudited) Statements 7 false false R8.htm 100070 - Disclosure - Nature of Business and Basis of Presentation Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureNatureOfBusinessAndBasisOfPresentation Nature of Business and Basis of Presentation Notes 8 false false R9.htm 100080 - Disclosure - Recent Accounting Pronouncements Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureRecentAccountingPronouncements Recent Accounting Pronouncements Notes 9 false false R10.htm 100090 - Disclosure - Accounts Receivable, Net Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsReceivableNet Accounts Receivable, Net Notes 10 false false R11.htm 100100 - Disclosure - Inventories Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureInventories Inventories Notes 11 false false R12.htm 100110 - Disclosure - Project Assets Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureProjectAssets Project Assets Notes 12 false false R13.htm 100120 - Disclosure - Other Current Assets Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherCurrentAssets Other Current Assets Notes 13 false false R14.htm 100130 - Disclosure - Other Assets Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherAssets Other Assets Notes 14 false false R15.htm 100140 - Disclosure - Accounts Payable Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsPayable Accounts Payable Notes 15 false false R16.htm 100150 - Disclosure - Accrued Liabilities Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccruedLiabilities Accrued Liabilities Notes 16 false false R17.htm 100160 - Disclosure - Stockholders' Equity Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureStockholdersEquity Stockholders' Equity Notes 17 false false R18.htm 100170 - Disclosure - Redeemable Preferred Stock Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureRedeemablePreferredStock Redeemable Preferred Stock Notes 18 false false R19.htm 100180 - Disclosure - Loss Per Share Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureLossPerShare Loss Per Share Notes 19 false false R20.htm 100190 - Disclosure - Restricted Cash Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureRestrictedCash Restricted Cash Notes 20 false false R21.htm 100200 - Disclosure - Debt and Financing Obligation Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureDebtAndFinancingObligation Debt and Financing Obligation Notes 21 false false R22.htm 100210 - Disclosure - Benefit Plans Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureBenefitPlans Benefit Plans Notes 22 false false R23.htm 100220 - Disclosure - Income Taxes Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureIncomeTaxes Income Taxes Notes 23 false false R24.htm 100230 - Disclosure - Commitments and Contingencies Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureCommitmentsAndContingencies Commitments and Contingencies Notes 24 false false R25.htm 100240 - Disclosure - Nature of Business and Basis of Presentation (Policies) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureNatureOfBusinessAndBasisOfPresentationPolicies Nature of Business and Basis of Presentation (Policies) Policies http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureRecentAccountingPronouncements 25 false false R26.htm 100250 - Disclosure - Accounts Receivable, Net (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsReceivableNetTables Accounts Receivable, Net (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsReceivableNet 26 false false R27.htm 100260 - Disclosure - Inventories (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureInventoriesTables Inventories (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureInventories 27 false false R28.htm 100270 - Disclosure - Other Current Assets (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherCurrentAssetsTables Other Current Assets (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherCurrentAssets 28 false false R29.htm 100280 - Disclosure - Other Assets (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherAssetsTables Other Assets (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherAssets 29 false false R30.htm 100290 - Disclosure - Accrued Liabilities (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccruedLiabilitiesTables Accrued Liabilities (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccruedLiabilities 30 false false R31.htm 100300 - Disclosure - Stockholders' Equity (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureStockholdersEquityTables Stockholders' Equity (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureStockholdersEquity 31 false false R32.htm 100310 - Disclosure - Loss Per Share (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureLossPerShareTables Loss Per Share (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureLossPerShare 32 false false R33.htm 100320 - Disclosure - Debt and Financing Obligation (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureDebtAndFinancingObligationTables Debt and Financing Obligation (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureDebtAndFinancingObligation 33 false false R34.htm 100330 - Disclosure - Commitments and Contingencies (Tables) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureCommitmentsAndContingenciesTables Commitments and Contingencies (Tables) Tables http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureCommitmentsAndContingencies 34 false false R35.htm 100340 - Disclosure - Nature of Business and Basis of Presentation - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureNatureOfBusinessAndBasisOfPresentationAdditionalInformationDetails Nature of Business and Basis of Presentation - Additional Information (Details) Details 35 false false R36.htm 100350 - Disclosure - Accounts Receivable, Net - Schedule of Accounts Receivable (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsReceivableNetScheduleOfAccountsReceivableDetails Accounts Receivable, Net - Schedule of Accounts Receivable (Details) Details 36 false false R37.htm 100360 - Disclosure - Accounts Receivable, Net - Schedule of Accounts Receivable (Details) (Parenthetical) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsReceivableNetScheduleOfAccountsReceivableDetailsParenthetical Accounts Receivable, Net - Schedule of Accounts Receivable (Details) (Parenthetical) Details 37 false false R38.htm 100370 - Disclosure - Accounts Receivable, Net - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsReceivableNetAdditionalInformationDetails Accounts Receivable, Net - Additional Information (Details) Details 38 false false R39.htm 100380 - Disclosure - Inventories - Components of Inventories (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureInventoriesComponentsOfInventoriesDetails Inventories - Components of Inventories (Details) Details 39 false false R40.htm 100390 - Disclosure - Inventories - Components of Inventories (Parenthetical) (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureInventoriesComponentsOfInventoriesParentheticalDetails Inventories - Components of Inventories (Parenthetical) (Details) Details 40 false false R41.htm 100400 - Disclosure - Project Assets - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureProjectAssetsAdditionalInformationDetails Project Assets - Additional Information (Details) Details 41 false false R42.htm 100410 - Disclosure - Other Current Assets - Schedule of Other Current Assets (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherCurrentAssetsScheduleOfOtherCurrentAssetsDetails Other Current Assets - Schedule of Other Current Assets (Details) Details 42 false false R43.htm 100420 - Disclosure - Other Current Assets - Schedule of Other Current Assets (Parenthetical) (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherCurrentAssetsScheduleOfOtherCurrentAssetsParentheticalDetails Other Current Assets - Schedule of Other Current Assets (Parenthetical) (Details) Details 43 false false R44.htm 100430 - Disclosure - Other Assets - Schedule of Other Assets (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherAssetsScheduleOfOtherAssetsDetails Other Assets - Schedule of Other Assets (Details) Details 44 false false R45.htm 100440 - Disclosure - Other Assets - Schedule of Other Assets (Parenthetical) (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureOtherAssetsScheduleOfOtherAssetsParentheticalDetails Other Assets - Schedule of Other Assets (Parenthetical) (Details) Details 45 false false R46.htm 100450 - Disclosure - Accounts Payable - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureAccountsPayableAdditionalInformationDetails Accounts Payable - Additional Information (Details) Details 46 false false R47.htm 100460 - Disclosure - Schedule of Accrued Liabilities (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureScheduleOfAccruedLiabilitiesDetails Schedule of Accrued Liabilities (Details) Details 47 false false R48.htm 100470 - Disclosure - Schedule of Accrued Liabilities (Parenthetical) (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureScheduleOfAccruedLiabilitiesParentheticalDetails Schedule of Accrued Liabilities (Parenthetical) (Details) Details 48 false false R49.htm 100480 - Disclosure - Stockholders' Equity - Schedule of Stockholders Equity (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureStockholdersEquityScheduleOfStockholdersEquityDetails Stockholders' Equity - Schedule of Stockholders Equity (Details) Details 49 false false R50.htm 100490 - Disclosure - Stockholders' Equity - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetails Stockholders' Equity - Additional Information (Details) Details 50 false false R51.htm 100500 - Disclosure - Stockholders' Equity - Schedule of Warrant Activity (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureStockholdersEquityScheduleOfWarrantActivityDetails Stockholders' Equity - Schedule of Warrant Activity (Details) Details 51 false false R52.htm 100510 - Disclosure - Redeemable Preferred Stock - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureRedeemablePreferredStockAdditionalInformationDetails Redeemable Preferred Stock - Additional Information (Details) Details 52 false false R53.htm 100520 - Disclosure - Loss Per Share - Calculation of Basic and Diluted Loss Per Share (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureLossPerShareCalculationOfBasicAndDilutedLossPerShareDetails Loss Per Share - Calculation of Basic and Diluted Loss Per Share (Details) Details 53 false false R54.htm 100530 - Disclosure - Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from the Diluted Loss Per Share Calculation (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureLossPerShareScheduleOfPotentiallyDilutiveSecuritiesExcludedFromDilutedLossPerShareCalculationDetails Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from the Diluted Loss Per Share Calculation (Details) Details 54 false false R55.htm 100540 - Disclosure - Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from the Diluted Loss Per Share Calculation (Parenthetical) (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureLossPerShareScheduleOfPotentiallyDilutiveSecuritiesExcludedFromDilutedLossPerShareCalculationParentheticalDetails Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from the Diluted Loss Per Share Calculation (Parenthetical) (Details) Details 55 false false R56.htm 100550 - Disclosure - Restricted Cash - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureRestrictedCashAdditionalInformationDetails Restricted Cash - Additional Information (Details) Details 56 false false R57.htm 100560 - Disclosure - Debt and Financing Obligation - Schedule of Debt (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureDebtAndFinancingObligationScheduleOfDebtDetails Debt and Financing Obligation - Schedule of Debt (Details) Details 57 false false R58.htm 100580 - Disclosure - Debt and Financing Obligation - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureDebtAndFinancingObligationAdditionalInformationDetails Debt and Financing Obligation - Additional Information (Details) Details 58 false false R59.htm 100590 - Disclosure - Benefit Plans - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureBenefitPlansAdditionalInformationDetails Benefit Plans - Additional Information (Details) Details 59 false false R60.htm 100600 - Disclosure - Income Taxes - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails Income Taxes - Additional Information (Details) Details 60 false false R61.htm 100610 - Disclosure - Commitments and Contingencies - Additional Information (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails Commitments and Contingencies - Additional Information (Details) Details 61 false false R62.htm 100620 - Disclosure - Commitments and Contingencies - Schedule of Non-Cancelable Minimum Payments Applicable to Operating and Capital Leases (Details) Sheet http://www.fuelcellenergy.com/20180430/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfNonCancelableMinimumPaymentsApplicableToOperatingAndCapitalLeasesDetails Commitments and Contingencies - Schedule of Non-Cancelable Minimum Payments Applicable to Operating and Capital Leases (Details) Details 62 false false All Reports Book All Reports fcel-20180430.xml fcel-20180430.xsd fcel-20180430_cal.xml fcel-20180430_def.xml fcel-20180430_lab.xml fcel-20180430_pre.xml http://xbrl.sec.gov/dei/2014-01-31 http://fasb.org/us-gaap/2017-01-31 true true