3.8.0.1 html 214 232 1 true 66 0 false 10 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/StatementCONDENSEDCONSOLIDATEDBALANCESHEETS CONDENSED CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 100020 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/StatementCONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 100030 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF INCOME Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/StatementCONDENSEDCONSOLIDATEDSTATEMENTSOFINCOME CONDENSED CONSOLIDATED STATEMENTS OF INCOME Statements 4 false false R5.htm 100040 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/StatementCONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Statements 5 false false R6.htm 100050 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/StatementCONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 6 false false R7.htm 100060 - Disclosure - Basis of Presentation Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureBasisOfPresentation Basis of Presentation Notes 7 false false R8.htm 100070 - Disclosure - Acquisitions Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureAcquisitions Acquisitions Notes 8 false false R9.htm 100080 - Disclosure - Cash, Cash Equivalents and Restricted Cash Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCash Cash, Cash Equivalents and Restricted Cash Notes 9 false false R10.htm 100090 - Disclosure - Earnings Per Share Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureEarningsPerShare Earnings Per Share Notes 10 false false R11.htm 100100 - Disclosure - Inventories, Net Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureInventoriesNet Inventories, Net Notes 11 false false R12.htm 100110 - Disclosure - Property, Plant and Equipment Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosurePropertyPlantAndEquipment Property, Plant and Equipment Notes 12 false false R13.htm 100120 - Disclosure - Stock-Based Compensation Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureStockBasedCompensation Stock-Based Compensation Notes 13 false false R14.htm 100130 - Disclosure - Intangible Assets Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssets Intangible Assets Notes 14 false false R15.htm 100140 - Disclosure - Dividends Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDividends Dividends Notes 15 false false R16.htm 100150 - Disclosure - Segment Information Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSegmentInformation Segment Information Notes 16 false false R17.htm 100160 - Disclosure - Long-Term Debt Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureLongTermDebt Long-Term Debt Notes 17 false false R18.htm 100170 - Disclosure - Fair Value Measurements Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureFairValueMeasurements Fair Value Measurements Notes 18 false false R19.htm 100180 - Disclosure - Derivative Financial Instruments Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDerivativeFinancialInstruments Derivative Financial Instruments Notes 19 false false R20.htm 100190 - Disclosure - Income Taxes Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIncomeTaxes Income Taxes Notes 20 false false R21.htm 100200 - Disclosure - Litigation and Other Contingencies Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureLitigationAndOtherContingencies Litigation and Other Contingencies Notes 21 false false R22.htm 100210 - Disclosure - Restructuring and Realignment Events Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRestructuringAndRealignmentEvents Restructuring and Realignment Events Notes 22 false false R23.htm 100220 - Disclosure - Acquisitions (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureAcquisitionsTables Acquisitions (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureAcquisitions 23 false false R24.htm 100230 - Disclosure - Cash, Cash Equivalents and Restricted Cash (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCashTables Cash, Cash Equivalents and Restricted Cash (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCash 24 false false R25.htm 100240 - Disclosure - Inventories, Net (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureInventoriesNetTables Inventories, Net (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureInventoriesNet 25 false false R26.htm 100250 - Disclosure - Property, Plant and Equipment (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosurePropertyPlantAndEquipmentTables Property, Plant and Equipment (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosurePropertyPlantAndEquipment 26 false false R27.htm 100260 - Disclosure - Stock-Based Compensation (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureStockBasedCompensationTables Stock-Based Compensation (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureStockBasedCompensation 27 false false R28.htm 100270 - Disclosure - Intangible Assets (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssetsTables Intangible Assets (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssets 28 false false R29.htm 100280 - Disclosure - Segment Information (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSegmentInformationTables Segment Information (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSegmentInformation 29 false false R30.htm 100290 - Disclosure - Long-Term Debt (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureLongTermDebtTables Long-Term Debt (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureLongTermDebt 30 false false R31.htm 100300 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureFairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureFairValueMeasurements 31 false false R32.htm 100310 - Disclosure - Derivative Financial Instruments (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDerivativeFinancialInstrumentsTables Derivative Financial Instruments (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDerivativeFinancialInstruments 32 false false R33.htm 100320 - Disclosure - Restructuring and Realignment Events (Tables) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRestructuringAndRealignmentEventsTables Restructuring and Realignment Events (Tables) Tables http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRestructuringAndRealignmentEvents 33 false false R34.htm 100330 - Disclosure - Acquisitions - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail Acquisitions - Additional Information (Detail) Details 34 false false R35.htm 100340 - Disclosure - Summary of Acquired Assets and Assumed Liabilities and Preliminary/Final Acquisition Accounting for Fair Value of Assets and Liabilities Recognized (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfAcquiredAssetsAndAssumedLiabilitiesAndPreliminaryFinalAcquisitionAccountingForFairValueOfAssetsAndLiabilitiesRecognizedDetail Summary of Acquired Assets and Assumed Liabilities and Preliminary/Final Acquisition Accounting for Fair Value of Assets and Liabilities Recognized (Detail) Details 35 false false R36.htm 100350 - Disclosure - Summary of Measurement Period Adjustments Made to Preliminary Purchase Price Allocation (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfMeasurementPeriodAdjustmentsMadeToPreliminaryPurchasePriceAllocationDetail Summary of Measurement Period Adjustments Made to Preliminary Purchase Price Allocation (Detail) Details 36 false false R37.htm 100360 - Disclosure - Cash, Cash Equivalents and Restricted Cash - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCashReconciliationOfCashCashEquivalentsAndRestrictedCashDetails Cash, Cash Equivalents and Restricted Cash - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) Details 37 false false R38.htm 100370 - Disclosure - Earnings per Share - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureEarningsPerShareAdditionalInformationDetail Earnings per Share - Additional Information (Detail) Details 38 false false R39.htm 100380 - Disclosure - Summary of Inventories, Net (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfInventoriesNetDetail Summary of Inventories, Net (Detail) Details 39 false false R40.htm 100390 - Disclosure - Property, Plant, and Equipment and Related Accumulated Depreciation and Amortization (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosurePropertyPlantAndEquipmentAndRelatedAccumulatedDepreciationAndAmortizationDetail Property, Plant, and Equipment and Related Accumulated Depreciation and Amortization (Detail) Details 40 false false R41.htm 100400 - Disclosure - Property, Plant, and Equipment and Related Accumulated Depreciation and Amortization (Parenthetical) (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosurePropertyPlantAndEquipmentAndRelatedAccumulatedDepreciationAndAmortizationParentheticalDetail Property, Plant, and Equipment and Related Accumulated Depreciation and Amortization (Parenthetical) (Detail) Details 41 false false R42.htm 100410 - Disclosure - Stock-Based Compensation - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail Stock-Based Compensation - Additional Information (Detail) Details 42 false false R43.htm 100420 - Disclosure - Summary of Performance Based RSU Awards (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfPerformanceBasedRSUAwardsDetail Summary of Performance Based RSU Awards (Detail) Details 43 false false R44.htm 100430 - Disclosure - Summary of Performance Based RSU Awards (Parenthetical) (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfPerformanceBasedRSUAwardsParentheticalDetail Summary of Performance Based RSU Awards (Parenthetical) (Detail) Details 44 false false R45.htm 100440 - Disclosure - Summary of Activity for Time-Based Stock Awards (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfActivityForTimeBasedStockAwardsDetail Summary of Activity for Time-Based Stock Awards (Detail) Details 45 false false R46.htm 100450 - Disclosure - Summary of Activity for Time-Based Stock Awards (Parenthetical) (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSummaryOfActivityForTimeBasedStockAwardsParentheticalDetail Summary of Activity for Time-Based Stock Awards (Parenthetical) (Detail) Details 46 false false R47.htm 100460 - Disclosure - Intangible Assets (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssetsDetail Intangible Assets (Detail) Details http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssetsTables 47 false false R48.htm 100470 - Disclosure - Intangible Assets (Parenthetical) (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssetsParentheticalDetail Intangible Assets (Parenthetical) (Detail) Details http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssetsTables 48 false false R49.htm 100480 - Disclosure - Intangible Assets - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIntangibleAssetsAdditionalInformationDetail Intangible Assets - Additional Information (Detail) Details 49 false false R50.htm 100490 - Disclosure - Dividends - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDividendsAdditionalInformationDetail Dividends - Additional Information (Detail) Details 50 false false R51.htm 100500 - Disclosure - Segment Information - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail Segment Information - Additional Information (Detail) Details 51 false false R52.htm 100510 - Disclosure - Segment Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSegmentInformationDetail Segment Information (Detail) Details http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureSegmentInformationTables 52 false false R53.htm 100520 - Disclosure - Schedule of Debt (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureScheduleOfDebtDetail Schedule of Debt (Detail) Details 53 false false R54.htm 100530 - Disclosure - Schedule of Debt (Parenthetical) (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureScheduleOfDebtParentheticalDetail Schedule of Debt (Parenthetical) (Detail) Details 54 false false R55.htm 100540 - Disclosure - Long-Term Debt - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureLongTermDebtAdditionalInformationDetail Long-Term Debt - Additional Information (Detail) Details 55 false false R56.htm 100550 - Disclosure - Ratio of Net Funded Debt to Adjusted EBITDA (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRatioOfNetFundedDebtToAdjustedEBITDADetail Ratio of Net Funded Debt to Adjusted EBITDA (Detail) Details 56 false false R57.htm 100560 - Disclosure - Ratio of Net Funded Debt to Adjusted EBITDA (Parenthetical) (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRatioOfNetFundedDebtToAdjustedEBITDAParentheticalDetail Ratio of Net Funded Debt to Adjusted EBITDA (Parenthetical) (Detail) Details 57 false false R58.htm 100570 - Disclosure - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureScheduleOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) Details 58 false false R59.htm 100580 - Disclosure - Derivative Financial Instruments - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetail Derivative Financial Instruments - Additional Information (Detail) Details 59 false false R60.htm 100590 - Disclosure - Derivative Financial Instruments - Summary of Combined Fair Value of Derivatives not Designated as Hedging Instruments included in Accompanying Condensed Consolidated Balance Sheet (Details) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDerivativeFinancialInstrumentsSummaryOfCombinedFairValueOfDerivativesNotDesignatedAsHedgingInstrumentsIncludedInAccompanyingCondensedConsolidatedBalanceSheetDetails Derivative Financial Instruments - Summary of Combined Fair Value of Derivatives not Designated as Hedging Instruments included in Accompanying Condensed Consolidated Balance Sheet (Details) Details 60 false false R61.htm 100600 - Disclosure - Derivative Financial Instruments - Summary of Effects of Derivatives not Designated as Hedging Instuments on Condensed Consolidated Statements of Income (Details) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureDerivativeFinancialInstrumentsSummaryOfEffectsOfDerivativesNotDesignatedAsHedgingInstumentsOnCondensedConsolidatedStatementsOfIncomeDetails Derivative Financial Instruments - Summary of Effects of Derivatives not Designated as Hedging Instuments on Condensed Consolidated Statements of Income (Details) Details 61 false false R62.htm 100610 - Disclosure - Income Taxes - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail Income Taxes - Additional Information (Detail) Details 62 false false R63.htm 100620 - Disclosure - Litigation and Other Contingencies - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureLitigationAndOtherContingenciesAdditionalInformationDetail Litigation and Other Contingencies - Additional Information (Detail) Details 63 false false R64.htm 100630 - Disclosure - Restructuring and Realignment Events - Additional Information (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRestructuringAndRealignmentEventsAdditionalInformationDetail Restructuring and Realignment Events - Additional Information (Detail) Details 64 false false R65.htm 100640 - Disclosure - Restructuring and Realignment Events - Accrued Liability Associated with Restructuring and Other Related Charges (Detail) Sheet http://www.kmgchemicals.com/20180131/taxonomy/role/DisclosureRestructuringAndRealignmentEventsAccruedLiabilityAssociatedWithRestructuringAndOtherRelatedChargesDetail Restructuring and Realignment Events - Accrued Liability Associated with Restructuring and Other Related Charges (Detail) Details 65 false false All Reports Book All Reports kmg-20180131.xml kmg-20180131.xsd kmg-20180131_cal.xml kmg-20180131_def.xml kmg-20180131_lab.xml kmg-20180131_pre.xml http://xbrl.sec.gov/invest/2013-01-31 http://fasb.org/us-gaap/2017-01-31 http://xbrl.sec.gov/dei/2014-01-31 true true