3.21.2 html 538 718 1 false 140 0 false 6 false false R1.htm 000010001 - Document - Cover Sheet http://www.evoqua.com/role/Cover Cover Cover 1 false false R2.htm 100010002 - Statement - Consolidated Balance Sheets Sheet http://www.evoqua.com/role/ConsolidatedBalanceSheets Consolidated Balance Sheets Statements 2 false false R3.htm 100020003 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.evoqua.com/role/ConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 3 false false R4.htm 100030004 - Statement - Consolidated Statements of Operations Sheet http://www.evoqua.com/role/ConsolidatedStatementsofOperations Consolidated Statements of Operations Statements 4 false false R5.htm 100040005 - Statement - Consolidated Statements of Comprehensive Income (Loss) Sheet http://www.evoqua.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss Consolidated Statements of Comprehensive Income (Loss) Statements 5 false false R6.htm 100050006 - Statement - Condensed Consolidated Statements of Changes in Equity Sheet http://www.evoqua.com/role/CondensedConsolidatedStatementsofChangesinEquity Condensed Consolidated Statements of Changes in Equity Statements 6 false false R7.htm 100060007 - Statement - Condensed Consolidated Statements of Changes in Cash Flows Sheet http://www.evoqua.com/role/CondensedConsolidatedStatementsofChangesinCashFlows Condensed Consolidated Statements of Changes in Cash Flows Statements 7 false false R8.htm 100070008 - Statement - Condensed Consolidated Statements of Changes in Cash Flows (Parenthetical) Sheet http://www.evoqua.com/role/CondensedConsolidatedStatementsofChangesinCashFlowsParenthetical Condensed Consolidated Statements of Changes in Cash Flows (Parenthetical) Statements 8 false false R9.htm 210011001 - Disclosure - Description of the Company and Basis of Presentation Sheet http://www.evoqua.com/role/DescriptionoftheCompanyandBasisofPresentation Description of the Company and Basis of Presentation Notes 9 false false R10.htm 210041002 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.evoqua.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 10 false false R11.htm 210081003 - Disclosure - Variable Interest Entities Sheet http://www.evoqua.com/role/VariableInterestEntities Variable Interest Entities Notes 11 false false R12.htm 210111004 - Disclosure - Acquisitions and Divestitures Sheet http://www.evoqua.com/role/AcquisitionsandDivestitures Acquisitions and Divestitures Notes 12 false false R13.htm 210181005 - Disclosure - Revenue Sheet http://www.evoqua.com/role/Revenue Revenue Notes 13 false false R14.htm 210241006 - Disclosure - Fair Value Measurements Sheet http://www.evoqua.com/role/FairValueMeasurements Fair Value Measurements Notes 14 false false R15.htm 210281007 - Disclosure - Accounts Receivable Sheet http://www.evoqua.com/role/AccountsReceivable Accounts Receivable Notes 15 false false R16.htm 210321008 - Disclosure - Inventories Sheet http://www.evoqua.com/role/Inventories Inventories Notes 16 false false R17.htm 210361009 - Disclosure - Property, Plant, and Equipment Sheet http://www.evoqua.com/role/PropertyPlantandEquipment Property, Plant, and Equipment Notes 17 false false R18.htm 210411010 - Disclosure - Goodwill Sheet http://www.evoqua.com/role/Goodwill Goodwill Notes 18 false false R19.htm 210451011 - Disclosure - Other Intangible Assets Sheet http://www.evoqua.com/role/OtherIntangibleAssets Other Intangible Assets Notes 19 false false R20.htm 210501012 - Disclosure - Debt Sheet http://www.evoqua.com/role/Debt Debt Notes 20 false false R21.htm 210591013 - Disclosure - Derivative Financial Instruments Sheet http://www.evoqua.com/role/DerivativeFinancialInstruments Derivative Financial Instruments Notes 21 false false R22.htm 210671014 - Disclosure - Product Warranties Sheet http://www.evoqua.com/role/ProductWarranties Product Warranties Notes 22 false false R23.htm 210701015 - Disclosure - Restructuring and Related Charges Sheet http://www.evoqua.com/role/RestructuringandRelatedCharges Restructuring and Related Charges Notes 23 false false R24.htm 210741016 - Disclosure - Employee Benefit Plans Sheet http://www.evoqua.com/role/EmployeeBenefitPlans Employee Benefit Plans Notes 24 false false R25.htm 210831017 - Disclosure - Income Taxes Sheet http://www.evoqua.com/role/IncomeTaxes Income Taxes Notes 25 false false R26.htm 210931018 - Disclosure - Share Based Compensation Sheet http://www.evoqua.com/role/ShareBasedCompensation Share Based Compensation Notes 26 false false R27.htm 211011019 - Disclosure - Other Comprehensive Loss Sheet http://www.evoqua.com/role/OtherComprehensiveLoss Other Comprehensive Loss Notes 27 false false R28.htm 211051020 - Disclosure - Concentration of Credit Risk Sheet http://www.evoqua.com/role/ConcentrationofCreditRisk Concentration of Credit Risk Notes 28 false false R29.htm 211091021 - Disclosure - Leases Sheet http://www.evoqua.com/role/Leases Leases Notes 29 false false R30.htm 211181022 - Disclosure - Commitments and Contingencies Sheet http://www.evoqua.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 30 false false R31.htm 211211023 - Disclosure - Accrued Expenses and Other Liabilities Sheet http://www.evoqua.com/role/AccruedExpensesandOtherLiabilities Accrued Expenses and Other Liabilities Notes 31 false false R32.htm 211241024 - Disclosure - Business Segments Sheet http://www.evoqua.com/role/BusinessSegments Business Segments Notes 32 false false R33.htm 211271025 - Disclosure - Earnings per share Sheet http://www.evoqua.com/role/Earningspershare Earnings per share Notes 33 false false R34.htm 211301026 - Disclosure - Subsequent Events Sheet http://www.evoqua.com/role/SubsequentEvents Subsequent Events Notes 34 false false R35.htm 211311027 - Disclosure - SCHEDULE??I - Evoqua Water Technologies Corp. Sheet http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorp SCHEDULE??I - Evoqua Water Technologies Corp. Notes 35 false false R36.htm 220022001 - Disclosure - Description of the Company and Basis of Presentation - (Policies) Sheet http://www.evoqua.com/role/DescriptionoftheCompanyandBasisofPresentationPolicies Description of the Company and Basis of Presentation - (Policies) Policies http://www.evoqua.com/role/SummaryofSignificantAccountingPolicies 36 false false R37.htm 220072002 - Disclosure - Accounting Policies (Policies) Sheet http://www.evoqua.com/role/AccountingPoliciesPolicies Accounting Policies (Policies) Policies http://www.evoqua.com/role/SummaryofSignificantAccountingPolicies 37 false false R38.htm 230053001 - Disclosure - Summary of Significant Accounting Policies (Tables) Sheet http://www.evoqua.com/role/SummaryofSignificantAccountingPoliciesTables Summary of Significant Accounting Policies (Tables) Tables http://www.evoqua.com/role/SummaryofSignificantAccountingPolicies 38 false false R39.htm 230123003 - Disclosure - Acquisitions and Divestitures (Tables) Sheet http://www.evoqua.com/role/AcquisitionsandDivestituresTables Acquisitions and Divestitures (Tables) Tables http://www.evoqua.com/role/AcquisitionsandDivestitures 39 false false R40.htm 230193004 - Disclosure - Revenue (Tables) Sheet http://www.evoqua.com/role/RevenueTables Revenue (Tables) Tables http://www.evoqua.com/role/Revenue 40 false false R41.htm 230253005 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.evoqua.com/role/FairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.evoqua.com/role/FairValueMeasurements 41 false false R42.htm 230293006 - Disclosure - Accounts Receivable (Tables) Sheet http://www.evoqua.com/role/AccountsReceivableTables Accounts Receivable (Tables) Tables http://www.evoqua.com/role/AccountsReceivable 42 false false R43.htm 230333007 - Disclosure - Inventories (Tables) Sheet http://www.evoqua.com/role/InventoriesTables Inventories (Tables) Tables http://www.evoqua.com/role/Inventories 43 false false R44.htm 230373008 - Disclosure - Property, Plant, and Equipment (Tables) Sheet http://www.evoqua.com/role/PropertyPlantandEquipmentTables Property, Plant, and Equipment (Tables) Tables http://www.evoqua.com/role/PropertyPlantandEquipment 44 false false R45.htm 230423009 - Disclosure - Goodwill (Tables) Sheet http://www.evoqua.com/role/GoodwillTables Goodwill (Tables) Tables http://www.evoqua.com/role/Goodwill 45 false false R46.htm 230463010 - Disclosure - Other Intangible Assets (Tables) Sheet http://www.evoqua.com/role/OtherIntangibleAssetsTables Other Intangible Assets (Tables) Tables http://www.evoqua.com/role/OtherIntangibleAssets 46 false false R47.htm 230513011 - Disclosure - Debt (Tables) Sheet http://www.evoqua.com/role/DebtTables Debt (Tables) Tables http://www.evoqua.com/role/Debt 47 false false R48.htm 230603012 - Disclosure - Derivative Financial Instruments (Tables) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables Derivative Financial Instruments (Tables) Tables http://www.evoqua.com/role/DerivativeFinancialInstruments 48 false false R49.htm 230683013 - Disclosure - Product Warranties (Tables) Sheet http://www.evoqua.com/role/ProductWarrantiesTables Product Warranties (Tables) Tables http://www.evoqua.com/role/ProductWarranties 49 false false R50.htm 230713014 - Disclosure - Restructuring and Related Charges (Tables) Sheet http://www.evoqua.com/role/RestructuringandRelatedChargesTables Restructuring and Related Charges (Tables) Tables http://www.evoqua.com/role/RestructuringandRelatedCharges 50 false false R51.htm 230753015 - Disclosure - Employee Benefit Plans (Tables) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansTables Employee Benefit Plans (Tables) Tables http://www.evoqua.com/role/EmployeeBenefitPlans 51 false false R52.htm 230843016 - Disclosure - Income Taxes (Tables) Sheet http://www.evoqua.com/role/IncomeTaxesTables Income Taxes (Tables) Tables http://www.evoqua.com/role/IncomeTaxes 52 false false R53.htm 230943017 - Disclosure - Share Based Compensation (Tables) Sheet http://www.evoqua.com/role/ShareBasedCompensationTables Share Based Compensation (Tables) Tables http://www.evoqua.com/role/ShareBasedCompensation 53 false false R54.htm 231023018 - Disclosure - Other Comprehensive Loss (Tables) Sheet http://www.evoqua.com/role/OtherComprehensiveLossTables Other Comprehensive Loss (Tables) Tables http://www.evoqua.com/role/OtherComprehensiveLoss 54 false false R55.htm 231063019 - Disclosure - Concentration of Credit Risk (Tables) Sheet http://www.evoqua.com/role/ConcentrationofCreditRiskTables Concentration of Credit Risk (Tables) Tables http://www.evoqua.com/role/ConcentrationofCreditRisk 55 false false R56.htm 231103020 - Disclosure - Leases (Tables) Sheet http://www.evoqua.com/role/LeasesTables Leases (Tables) Tables http://www.evoqua.com/role/Leases 56 false false R57.htm 231193021 - Disclosure - Commitments and Contingencies (Tables) Sheet http://www.evoqua.com/role/CommitmentsandContingenciesTables Commitments and Contingencies (Tables) Tables http://www.evoqua.com/role/CommitmentsandContingencies 57 false false R58.htm 231223022 - Disclosure - Accrued Expenses and Other Liabilities (Tables) Sheet http://www.evoqua.com/role/AccruedExpensesandOtherLiabilitiesTables Accrued Expenses and Other Liabilities (Tables) Tables http://www.evoqua.com/role/AccruedExpensesandOtherLiabilities 58 false false R59.htm 231253023 - Disclosure - Business Segments (Tables) Sheet http://www.evoqua.com/role/BusinessSegmentsTables Business Segments (Tables) Tables http://www.evoqua.com/role/BusinessSegments 59 false false R60.htm 231283024 - Disclosure - Earnings per share (Tables) Sheet http://www.evoqua.com/role/EarningspershareTables Earnings per share (Tables) Tables http://www.evoqua.com/role/Earningspershare 60 false false R61.htm 231323025 - Disclosure - SCHEDULE??I - Evoqua Water Technologies Corp. (Tables) Sheet http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorpTables SCHEDULE??I - Evoqua Water Technologies Corp. (Tables) Tables http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorp 61 false false R62.htm 240034001 - Disclosure - Description of the Company and Basis of Presentation (Details) Sheet http://www.evoqua.com/role/DescriptionoftheCompanyandBasisofPresentationDetails Description of the Company and Basis of Presentation (Details) Details http://www.evoqua.com/role/DescriptionoftheCompanyandBasisofPresentationPolicies 62 false false R63.htm 240064002 - Disclosure - Summary of Significant Accounting Policies (Details) Sheet http://www.evoqua.com/role/SummaryofSignificantAccountingPoliciesDetails Summary of Significant Accounting Policies (Details) Details http://www.evoqua.com/role/SummaryofSignificantAccountingPoliciesTables 63 false false R64.htm 240104003 - Disclosure - Variable Interest Entities (Details) Sheet http://www.evoqua.com/role/VariableInterestEntitiesDetails Variable Interest Entities (Details) Details http://www.evoqua.com/role/VariableInterestEntities 64 false false R65.htm 240134004 - Disclosure - Acquisitions and Divestitures (WCSI Acquisition) (Details) Sheet http://www.evoqua.com/role/AcquisitionsandDivestituresWCSIAcquisitionDetails Acquisitions and Divestitures (WCSI Acquisition) (Details) Details http://www.evoqua.com/role/AcquisitionsandDivestituresTables 65 false false R66.htm 240144005 - Disclosure - Acquisitions and Divestitures (Ultrapure Acquisition) (Details) Sheet http://www.evoqua.com/role/AcquisitionsandDivestituresUltrapureAcquisitionDetails Acquisitions and Divestitures (Ultrapure Acquisition) (Details) Details http://www.evoqua.com/role/AcquisitionsandDivestituresTables 66 false false R67.htm 240154006 - Disclosure - Acquisitions and Divestitures (Lange Divestiture) (Details) Sheet http://www.evoqua.com/role/AcquisitionsandDivestituresLangeDivestitureDetails Acquisitions and Divestitures (Lange Divestiture) (Details) Details http://www.evoqua.com/role/AcquisitionsandDivestituresTables 67 false false R68.htm 240164007 - Disclosure - Acquisitions and Divestitures (Frontier Acquisition) (Details) Sheet http://www.evoqua.com/role/AcquisitionsandDivestituresFrontierAcquisitionDetails Acquisitions and Divestitures (Frontier Acquisition) (Details) Details http://www.evoqua.com/role/AcquisitionsandDivestituresTables 68 false false R69.htm 240174008 - Disclosure - Acquisitions and Divestitures (Memcor Divestiture) (Details) Sheet http://www.evoqua.com/role/AcquisitionsandDivestituresMemcorDivestitureDetails Acquisitions and Divestitures (Memcor Divestiture) (Details) Details http://www.evoqua.com/role/AcquisitionsandDivestituresTables 69 false false R70.htm 240204009 - Disclosure - Revenue (Details) Sheet http://www.evoqua.com/role/RevenueDetails Revenue (Details) Details http://www.evoqua.com/role/RevenueTables 70 false false R71.htm 240214010 - Disclosure - Revenue (Disaggregation of Revenue) (Details) Sheet http://www.evoqua.com/role/RevenueDisaggregationofRevenueDetails Revenue (Disaggregation of Revenue) (Details) Details http://www.evoqua.com/role/RevenueTables 71 false false R72.htm 240224011 - Disclosure - Revenue (Performance Obligations) (Details) Sheet http://www.evoqua.com/role/RevenuePerformanceObligationsDetails Revenue (Performance Obligations) (Details) Details http://www.evoqua.com/role/RevenueTables 72 false false R73.htm 240234012 - Disclosure - Revenue (Contract Assets and Liabilities) (Details) Sheet http://www.evoqua.com/role/RevenueContractAssetsandLiabilitiesDetails Revenue (Contract Assets and Liabilities) (Details) Details http://www.evoqua.com/role/RevenueTables 73 false false R74.htm 240264013 - Disclosure - Fair Value Measurements (Details) Sheet http://www.evoqua.com/role/FairValueMeasurementsDetails Fair Value Measurements (Details) Details http://www.evoqua.com/role/FairValueMeasurementsTables 74 false false R75.htm 240274014 - Disclosure - Fair Value Measurements (Rollforward of acquisition earnouts) (Details) Sheet http://www.evoqua.com/role/FairValueMeasurementsRollforwardofacquisitionearnoutsDetails Fair Value Measurements (Rollforward of acquisition earnouts) (Details) Details http://www.evoqua.com/role/FairValueMeasurementsTables 75 false false R76.htm 240304015 - Disclosure - Accounts Receivable (Details) Sheet http://www.evoqua.com/role/AccountsReceivableDetails Accounts Receivable (Details) Details http://www.evoqua.com/role/AccountsReceivableTables 76 false false R77.htm 240314016 - Disclosure - Accounts Receivable - Movement in the allowance for credit losses (Details) Sheet http://www.evoqua.com/role/AccountsReceivableMovementintheallowanceforcreditlossesDetails Accounts Receivable - Movement in the allowance for credit losses (Details) Details 77 false false R78.htm 240344017 - Disclosure - Inventories (Schedule of Major Classes of Inventory) (Details) Sheet http://www.evoqua.com/role/InventoriesScheduleofMajorClassesofInventoryDetails Inventories (Schedule of Major Classes of Inventory) (Details) Details http://www.evoqua.com/role/InventoriesTables 78 false false R79.htm 240354018 - Disclosure - Inventories (Activity in Reserves for Excess and Obsolete Inventory) (Details) Sheet http://www.evoqua.com/role/InventoriesActivityinReservesforExcessandObsoleteInventoryDetails Inventories (Activity in Reserves for Excess and Obsolete Inventory) (Details) Details http://www.evoqua.com/role/InventoriesTables 79 false false R80.htm 240384019 - Disclosure - Property, Plant, and Equipment (Details) Sheet http://www.evoqua.com/role/PropertyPlantandEquipmentDetails Property, Plant, and Equipment (Details) Details http://www.evoqua.com/role/PropertyPlantandEquipmentTables 80 false false R81.htm 240394020 - Disclosure - Property, Plant, and Equipment (Secured Financings) (Details) Sheet http://www.evoqua.com/role/PropertyPlantandEquipmentSecuredFinancingsDetails Property, Plant, and Equipment (Secured Financings) (Details) Details http://www.evoqua.com/role/PropertyPlantandEquipmentTables 81 false false R82.htm 240404021 - Disclosure - Property, Plant, and Equipment (Depreciation and maintenance and repairs expense) (Details) Sheet http://www.evoqua.com/role/PropertyPlantandEquipmentDepreciationandmaintenanceandrepairsexpenseDetails Property, Plant, and Equipment (Depreciation and maintenance and repairs expense) (Details) Details http://www.evoqua.com/role/PropertyPlantandEquipmentTables 82 false false R83.htm 240434022 - Disclosure - Goodwill (Details) Sheet http://www.evoqua.com/role/GoodwillDetails Goodwill (Details) Details http://www.evoqua.com/role/GoodwillTables 83 false false R84.htm 240444023 - Disclosure - Goodwill (Schedule) (Details) Sheet http://www.evoqua.com/role/GoodwillScheduleDetails Goodwill (Schedule) (Details) Details http://www.evoqua.com/role/GoodwillTables 84 false false R85.htm 240474024 - Disclosure - Other Intangible Assets (Details) Sheet http://www.evoqua.com/role/OtherIntangibleAssetsDetails Other Intangible Assets (Details) Details http://www.evoqua.com/role/OtherIntangibleAssetsTables 85 false false R86.htm 240484025 - Disclosure - Other Intangible Assets (Remaining weighted-average amortization period) (Details) Sheet http://www.evoqua.com/role/OtherIntangibleAssetsRemainingweightedaverageamortizationperiodDetails Other Intangible Assets (Remaining weighted-average amortization period) (Details) Details http://www.evoqua.com/role/OtherIntangibleAssetsTables 86 false false R87.htm 240494026 - Disclosure - Other Intangible Assets (Estimated future amortization expense) (Details) Sheet http://www.evoqua.com/role/OtherIntangibleAssetsEstimatedfutureamortizationexpenseDetails Other Intangible Assets (Estimated future amortization expense) (Details) Details http://www.evoqua.com/role/OtherIntangibleAssetsTables 87 false false R88.htm 240524027 - Disclosure - Debt (Schedule of Long-term Debt) (Details) Sheet http://www.evoqua.com/role/DebtScheduleofLongtermDebtDetails Debt (Schedule of Long-term Debt) (Details) Details http://www.evoqua.com/role/DebtTables 88 false false R89.htm 240534028 - Disclosure - Debt (Term Facilities and Revolving Credit Facility) (Details) Sheet http://www.evoqua.com/role/DebtTermFacilitiesandRevolvingCreditFacilityDetails Debt (Term Facilities and Revolving Credit Facility) (Details) Details http://www.evoqua.com/role/DebtTables 89 false false R90.htm 240544029 - Disclosure - Debt (Accounts Receivable Securitization) (Details) Sheet http://www.evoqua.com/role/DebtAccountsReceivableSecuritizationDetails Debt (Accounts Receivable Securitization) (Details) Details http://www.evoqua.com/role/DebtTables 90 false false R91.htm 240554030 - Disclosure - Debt (Schedule of Line of Credit Facilities) (Details) Sheet http://www.evoqua.com/role/DebtScheduleofLineofCreditFacilitiesDetails Debt (Schedule of Line of Credit Facilities) (Details) Details http://www.evoqua.com/role/DebtTables 91 false false R92.htm 240564031 - Disclosure - Debt (Long-term Debt Maturities) (Details) Sheet http://www.evoqua.com/role/DebtLongtermDebtMaturitiesDetails Debt (Long-term Debt Maturities) (Details) Details http://www.evoqua.com/role/DebtTables 92 false false R93.htm 240574032 - Disclosure - Debt (Equipment Financings) (Details) Sheet http://www.evoqua.com/role/DebtEquipmentFinancingsDetails Debt (Equipment Financings) (Details) Details http://www.evoqua.com/role/DebtTables 93 false false R94.htm 240584033 - Disclosure - Debt (Deferred Financing Fees) (Details) Sheet http://www.evoqua.com/role/DebtDeferredFinancingFeesDetails Debt (Deferred Financing Fees) (Details) Details http://www.evoqua.com/role/DebtTables 94 false false R95.htm 240614034 - Disclosure - Derivative Financial Instruments (Details) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsDetails Derivative Financial Instruments (Details) Details http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables 95 false false R96.htm 240624035 - Disclosure - Derivative Financial Instruments (Fair Values) (Details) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsFairValuesDetails Derivative Financial Instruments (Fair Values) (Details) Details http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables 96 false false R97.htm 240634036 - Disclosure - Derivative Financial Instruments (Amounts Recognized in AOCI) (Details) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsAmountsRecognizedinAOCIDetails Derivative Financial Instruments (Amounts Recognized in AOCI) (Details) Details http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables 97 false false R98.htm 240644037 - Disclosure - Derivative Financial Instruments (Amounts Reclassified out of AOCI) (Details) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsAmountsReclassifiedoutofAOCIDetails Derivative Financial Instruments (Amounts Reclassified out of AOCI) (Details) Details http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables 98 false false R99.htm 240654038 - Disclosure - Derivative Financial Instruments (Derivatives Not Designated for Hedging) (Details) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsDerivativesNotDesignatedforHedgingDetails Derivative Financial Instruments (Derivatives Not Designated for Hedging) (Details) Details http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables 99 false false R100.htm 240664039 - Disclosure - Derivative Financial Instruments (Location of Loss Recognized in Earnings) (Details) Sheet http://www.evoqua.com/role/DerivativeFinancialInstrumentsLocationofLossRecognizedinEarningsDetails Derivative Financial Instruments (Location of Loss Recognized in Earnings) (Details) Details http://www.evoqua.com/role/DerivativeFinancialInstrumentsTables 100 false false R101.htm 240694040 - Disclosure - Product Warranties (Details) Sheet http://www.evoqua.com/role/ProductWarrantiesDetails Product Warranties (Details) Details http://www.evoqua.com/role/ProductWarrantiesTables 101 false false R102.htm 240724041 - Disclosure - Restructuring and Related Charges (Details) Sheet http://www.evoqua.com/role/RestructuringandRelatedChargesDetails Restructuring and Related Charges (Details) Details http://www.evoqua.com/role/RestructuringandRelatedChargesTables 102 false false R103.htm 240734042 - Disclosure - Restructuring and Related Charges (Location of restructuring amounts) (Details) Sheet http://www.evoqua.com/role/RestructuringandRelatedChargesLocationofrestructuringamountsDetails Restructuring and Related Charges (Location of restructuring amounts) (Details) Details http://www.evoqua.com/role/RestructuringandRelatedChargesTables 103 false false R104.htm 240764043 - Disclosure - Employee Benefit Plans - Narrative (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansNarrativeDetails Employee Benefit Plans - Narrative (Details) Details 104 false false R105.htm 240774044 - Disclosure - Employee Benefit Plans (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansDetails Employee Benefit Plans (Details) Details http://www.evoqua.com/role/EmployeeBenefitPlansTables 105 false false R106.htm 240784045 - Disclosure - Employee Benefit Plans Change in Projected Benefit Obligation and Plan Assets (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansChangeinProjectedBenefitObligationandPlanAssetsDetails Employee Benefit Plans Change in Projected Benefit Obligation and Plan Assets (Details) Details 106 false false R107.htm 240794046 - Disclosure - Employee Benefit Plans Projected Benefit Obligation and Accumulated Benefit Obligation are in Excess of Plan Assets (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansProjectedBenefitObligationandAccumulatedBenefitObligationareinExcessofPlanAssetsDetails Employee Benefit Plans Projected Benefit Obligation and Accumulated Benefit Obligation are in Excess of Plan Assets (Details) Details 107 false false R108.htm 240804047 - Disclosure - Employee Benefit Plans Weighted Average Assumptions (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansWeightedAverageAssumptionsDetails Employee Benefit Plans Weighted Average Assumptions (Details) Details 108 false false R109.htm 240814048 - Disclosure - Employee Benefit Plans Allocation of Plan Assets (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansAllocationofPlanAssetsDetails Employee Benefit Plans Allocation of Plan Assets (Details) Details 109 false false R110.htm 240824049 - Disclosure - Employee Benefit Plans Benefits expected to be paid (Details) Sheet http://www.evoqua.com/role/EmployeeBenefitPlansBenefitsexpectedtobepaidDetails Employee Benefit Plans Benefits expected to be paid (Details) Details 110 false false R111.htm 240854050 - Disclosure - Income Taxes (Details) Sheet http://www.evoqua.com/role/IncomeTaxesDetails Income Taxes (Details) Details http://www.evoqua.com/role/IncomeTaxesTables 111 false false R112.htm 240864051 - Disclosure - Income Taxes Summary of Income Before Income Taxes (Details) Sheet http://www.evoqua.com/role/IncomeTaxesSummaryofIncomeBeforeIncomeTaxesDetails Income Taxes Summary of Income Before Income Taxes (Details) Details 112 false false R113.htm 240874052 - Disclosure - Income Taxes Components of Income Tax Expense (Details) Sheet http://www.evoqua.com/role/IncomeTaxesComponentsofIncomeTaxExpenseDetails Income Taxes Components of Income Tax Expense (Details) Details 113 false false R114.htm 240884053 - Disclosure - Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) Sheet http://www.evoqua.com/role/IncomeTaxesScheduleofEffectiveIncomeTaxRateReconciliationDetails Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) Details 114 false false R115.htm 240894054 - Disclosure - Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) Sheet http://www.evoqua.com/role/IncomeTaxesScheduleofDeferredTaxAssetsandLiabilitiesDetails Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) Details 115 false false R116.htm 240904055 - Disclosure - Income Taxes Tax attributes available to reduce future taxable income (Details) Sheet http://www.evoqua.com/role/IncomeTaxesTaxattributesavailabletoreducefuturetaxableincomeDetails Income Taxes Tax attributes available to reduce future taxable income (Details) Details 116 false false R117.htm 240914056 - Disclosure - Income Taxes Reconciliation of our valuation allowance on deferred tax assets (Details) Sheet http://www.evoqua.com/role/IncomeTaxesReconciliationofourvaluationallowanceondeferredtaxassetsDetails Income Taxes Reconciliation of our valuation allowance on deferred tax assets (Details) Details 117 false false R118.htm 240924057 - Disclosure - Income Taxes Gross Unrecognized Tax Benefits Rollforward (Details) Sheet http://www.evoqua.com/role/IncomeTaxesGrossUnrecognizedTaxBenefitsRollforwardDetails Income Taxes Gross Unrecognized Tax Benefits Rollforward (Details) Details 118 false false R119.htm 240954058 - Disclosure - Share Based Compensation (Narrative) (Details) Sheet http://www.evoqua.com/role/ShareBasedCompensationNarrativeDetails Share Based Compensation (Narrative) (Details) Details http://www.evoqua.com/role/ShareBasedCompensationTables 119 false false R120.htm 240964059 - Disclosure - Share Based Compensation (Stock Option Activity) (Details) Sheet http://www.evoqua.com/role/ShareBasedCompensationStockOptionActivityDetails Share Based Compensation (Stock Option Activity) (Details) Details http://www.evoqua.com/role/ShareBasedCompensationTables 120 false false R121.htm 240974060 - Disclosure - Share Based Compensation (Nonvested Share Activity) (Details) Sheet http://www.evoqua.com/role/ShareBasedCompensationNonvestedShareActivityDetails Share Based Compensation (Nonvested Share Activity) (Details) Details http://www.evoqua.com/role/ShareBasedCompensationTables 121 false false R122.htm 240984061 - Disclosure - Share Based Compensation (RSU Activity) (Details) Sheet http://www.evoqua.com/role/ShareBasedCompensationRSUActivityDetails Share Based Compensation (RSU Activity) (Details) Details http://www.evoqua.com/role/ShareBasedCompensationTables 122 false false R123.htm 240994062 - Disclosure - Share Based Compensation (Valuation Assumptions for Options Granted) (Details) Sheet http://www.evoqua.com/role/ShareBasedCompensationValuationAssumptionsforOptionsGrantedDetails Share Based Compensation (Valuation Assumptions for Options Granted) (Details) Details http://www.evoqua.com/role/ShareBasedCompensationTables 123 false false R124.htm 241004063 - Disclosure - Share Based Compensation (Share-based compensation expense classified in the Consolidated Statements of Operations) (Details) Sheet http://www.evoqua.com/role/ShareBasedCompensationSharebasedcompensationexpenseclassifiedintheConsolidatedStatementsofOperationsDetails Share Based Compensation (Share-based compensation expense classified in the Consolidated Statements of Operations) (Details) Details http://www.evoqua.com/role/ShareBasedCompensationTables 124 false false R125.htm 241034064 - Disclosure - Other Comprehensive Loss (Components of Accumulated Other Comprehensive Income) (Details) Sheet http://www.evoqua.com/role/OtherComprehensiveLossComponentsofAccumulatedOtherComprehensiveIncomeDetails Other Comprehensive Loss (Components of Accumulated Other Comprehensive Income) (Details) Details http://www.evoqua.com/role/OtherComprehensiveLossTables 125 false false R126.htm 241044065 - Disclosure - Other Comprehensive Loss (Gains (losses) in Accumulated Other Comprehensive Loss) (Details) Sheet http://www.evoqua.com/role/OtherComprehensiveLossGainslossesinAccumulatedOtherComprehensiveLossDetails Other Comprehensive Loss (Gains (losses) in Accumulated Other Comprehensive Loss) (Details) Details http://www.evoqua.com/role/OtherComprehensiveLossTables 126 false false R127.htm 241074066 - Disclosure - Concentration of Credit Risk (Details) Sheet http://www.evoqua.com/role/ConcentrationofCreditRiskDetails Concentration of Credit Risk (Details) Details http://www.evoqua.com/role/ConcentrationofCreditRiskTables 127 false false R128.htm 241084067 - Disclosure - Concentration of Credit Risk - External net revenue, net of intercompany eliminations, and net asset information by region (Details) Sheet http://www.evoqua.com/role/ConcentrationofCreditRiskExternalnetrevenuenetofintercompanyeliminationsandnetassetinformationbyregionDetails Concentration of Credit Risk - External net revenue, net of intercompany eliminations, and net asset information by region (Details) Details 128 false false R129.htm 241114068 - Disclosure - Leases (Leases, Lessee Disclosures) (Details) Sheet http://www.evoqua.com/role/LeasesLeasesLesseeDisclosuresDetails Leases (Leases, Lessee Disclosures) (Details) Details http://www.evoqua.com/role/LeasesTables 129 false false R130.htm 241124069 - Disclosure - Leases (Operating Leases Future Payments) (Details) Sheet http://www.evoqua.com/role/LeasesOperatingLeasesFuturePaymentsDetails Leases (Operating Leases Future Payments) (Details) Details http://www.evoqua.com/role/LeasesTables 130 false false R131.htm 241134070 - Disclosure - Leases (Finance Lease Assets) (Details) Sheet http://www.evoqua.com/role/LeasesFinanceLeaseAssetsDetails Leases (Finance Lease Assets) (Details) Details http://www.evoqua.com/role/LeasesTables 131 false false R132.htm 241144071 - Disclosure - Leases (Finance Lease Maturities) (Details) Sheet http://www.evoqua.com/role/LeasesFinanceLeaseMaturitiesDetails Leases (Finance Lease Maturities) (Details) Details http://www.evoqua.com/role/LeasesTables 132 false false R133.htm 241154072 - Disclosure - Leases (Components of Lease Revenue (Details) Sheet http://www.evoqua.com/role/LeasesComponentsofLeaseRevenueDetails Leases (Components of Lease Revenue (Details) Details http://www.evoqua.com/role/LeasesTables 133 false false R134.htm 241164073 - Disclosure - Leases (Lessor Operating Lease Future Receivables) (Details) Sheet http://www.evoqua.com/role/LeasesLessorOperatingLeaseFutureReceivablesDetails Leases (Lessor Operating Lease Future Receivables) (Details) Details http://www.evoqua.com/role/LeasesTables 134 false false R135.htm 241174074 - Disclosure - Leases (Sales Type Leases) (Details) Sheet http://www.evoqua.com/role/LeasesSalesTypeLeasesDetails Leases (Sales Type Leases) (Details) Details http://www.evoqua.com/role/LeasesTables 135 false false R136.htm 241204075 - Disclosure - Commitments and Contingencies (Schedule of Letters of Credit and Surety Bonds) (Details) Sheet http://www.evoqua.com/role/CommitmentsandContingenciesScheduleofLettersofCreditandSuretyBondsDetails Commitments and Contingencies (Schedule of Letters of Credit and Surety Bonds) (Details) Details http://www.evoqua.com/role/CommitmentsandContingenciesTables 136 false false R137.htm 241234076 - Disclosure - Accrued Expenses and Other Liabilities (Details) Sheet http://www.evoqua.com/role/AccruedExpensesandOtherLiabilitiesDetails Accrued Expenses and Other Liabilities (Details) Details http://www.evoqua.com/role/AccruedExpensesandOtherLiabilitiesTables 137 false false R138.htm 241264077 - Disclosure - Business Segments (Details) Sheet http://www.evoqua.com/role/BusinessSegmentsDetails Business Segments (Details) Details http://www.evoqua.com/role/BusinessSegmentsTables 138 false false R139.htm 241294078 - Disclosure - Earnings per share (Details) Sheet http://www.evoqua.com/role/EarningspershareDetails Earnings per share (Details) Details http://www.evoqua.com/role/EarningspershareTables 139 false false R140.htm 241334079 - Disclosure - SCHEDULE??I - Evoqua Water Technologies Corp. Condensed Consolidated Balance Sheets (Details) Sheet http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorpCondensedConsolidatedBalanceSheetsDetails SCHEDULE??I - Evoqua Water Technologies Corp. Condensed Consolidated Balance Sheets (Details) Details 140 false false R141.htm 241344080 - Disclosure - SCHEDULE??I - Evoqua Water Technologies Corp. Condensed Statements of Operations (Details) Sheet http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorpCondensedStatementsofOperationsDetails SCHEDULE??I - Evoqua Water Technologies Corp. Condensed Statements of Operations (Details) Details 141 false false R142.htm 241354081 - Disclosure - SCHEDULE??I - Evoqua Water Technologies Corp. Condensed Statements of Changes in Cash Flows (Details) Sheet http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorpCondensedStatementsofChangesinCashFlowsDetails SCHEDULE??I - Evoqua Water Technologies Corp. Condensed Statements of Changes in Cash Flows (Details) Details 142 false false R143.htm 241364082 - Disclosure - SCHEDULE??I - Evoqua Water Technologies Corp. (Details) Sheet http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorpDetails SCHEDULE??I - Evoqua Water Technologies Corp. (Details) Details http://www.evoqua.com/role/SCHEDULEIEvoquaWaterTechnologiesCorpTables 143 false false All Reports Book All Reports aqua-20210930.htm aqua-20210930.xsd aqua-20210930_cal.xml aqua-20210930_def.xml aqua-20210930_lab.xml aqua-20210930_pre.xml fy21q4ex103firstamendmentt.htm fy21q4ex104secondamendment.htm q4fy21ceocertexhibit311.htm q4fy21cfocertexhibit312.htm q4fy21ex1028amendedandrest.htm q4fy21ex1033formofnon-empl.htm q4fy21exhibit211.htm q4fy21soxcertexhibit321.htm q4fy21soxcertexhibit322.htm q4fyex231consentofernstyou.htm aqua-20210930_g1.gif aqua-20210930_g2.jpg aqua-20210930_g3.jpg aqua-20210930_g4.jpg aqua-20210930_g5.jpg aqua-20210930_g6.jpg aqua-20210930_g7.jpg http://xbrl.sec.gov/dei/2021 http://fasb.org/us-gaap/2021-01-31 http://fasb.org/srt/2021-01-31 http://xbrl.sec.gov/country/2021 true true