3.10.0.1 html 479 476 1 true 118 0 false 14 false false R1.htm 0001000 - Document - Document and Entity Information Sheet http://www.cmc.com/role/DocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 1001000 - Statement - CONSOLIDATED STATEMENTS OF EARNINGS Sheet http://www.cmc.com/role/ConsolidatedStatementsOfEarnings CONSOLIDATED STATEMENTS OF EARNINGS Statements 2 false false R3.htm 1002500 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Sheet http://www.cmc.com/role/ConsolidatedStatementsOfComprehensiveIncome CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Statements 3 false false R4.htm 1003000 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.cmc.com/role/ConsolidatedBalanceSheets CONSOLIDATED BALANCE SHEETS Statements 4 false false R5.htm 1003501 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.cmc.com/role/ConsolidatedBalanceSheetsParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 5 false false R6.htm 1004000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.cmc.com/role/ConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 6 false false R7.htm 1004001 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS (Parenthetical) Sheet http://www.cmc.com/role/ConsolidatedStatementOfCashFlowsParenthetical CONSOLIDATED STATEMENT OF CASH FLOWS (Parenthetical) Statements 7 false false R8.htm 1006000 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Sheet http://www.cmc.com/role/ConsolidatedStatementsOfStockholdersEquity CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Statements 8 false false R9.htm 1006501 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) Sheet http://www.cmc.com/role/ConsolidatedStatementsOfStockholdersEquityParenthetical CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) Statements 9 false false R10.htm 2101100 - Disclosure - NATURE OF OPERATIONS Sheet http://www.cmc.com/role/NatureOfOperations NATURE OF OPERATIONS Notes 10 false false R11.htm 2102100 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Sheet http://www.cmc.com/role/SummaryOfSignificantAccountingPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Notes 11 false false R12.htm 2104100 - Disclosure - CHANGES IN BUSINESS Sheet http://www.cmc.com/role/ChangesInBusiness CHANGES IN BUSINESS Notes 12 false false R13.htm 2106100 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Sheet http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLoss ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Notes 13 false false R14.htm 2107100 - Disclosure - SALES OF ACCOUNTS RECEIVABLE Sheet http://www.cmc.com/role/SalesOfAccountsReceivable SALES OF ACCOUNTS RECEIVABLE Notes 14 false false R15.htm 2108100 - Disclosure - INVENTORIES Sheet http://www.cmc.com/role/Inventories INVENTORIES Notes 15 false false R16.htm 2109100 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS Sheet http://www.cmc.com/role/GoodwillAndOtherIntangibleAssets GOODWILL AND OTHER INTANGIBLE ASSETS Notes 16 false false R17.htm 2110100 - Disclosure - LONG-LIVED ASSET IMPAIRMENTS Sheet http://www.cmc.com/role/LongLivedAssetImpairments LONG-LIVED ASSET IMPAIRMENTS Notes 17 false false R18.htm 2111100 - Disclosure - EXIT COSTS Sheet http://www.cmc.com/role/ExitCosts EXIT COSTS Notes 18 false false R19.htm 2113100 - Disclosure - CREDIT ARRANGEMENTS Sheet http://www.cmc.com/role/CreditArrangements CREDIT ARRANGEMENTS Notes 19 false false R20.htm 2114100 - Disclosure - NEW MARKETS TAX CREDIT TRANSACTIONS Sheet http://www.cmc.com/role/NewMarketsTaxCreditTransactions NEW MARKETS TAX CREDIT TRANSACTIONS Notes 20 false false R21.htm 2115100 - Disclosure - DERIVATIVES AND RISK MANAGEMENT Sheet http://www.cmc.com/role/DerivativesAndRiskManagement DERIVATIVES AND RISK MANAGEMENT Notes 21 false false R22.htm 2116100 - Disclosure - FAIR VALUE Sheet http://www.cmc.com/role/FairValue FAIR VALUE Notes 22 false false R23.htm 2117100 - Disclosure - INCOME TAX Sheet http://www.cmc.com/role/IncomeTax INCOME TAX Notes 23 false false R24.htm 2118100 - Disclosure - STOCK-BASED COMPENSATION PLANS Sheet http://www.cmc.com/role/StockBasedCompensationPlans STOCK-BASED COMPENSATION PLANS Notes 24 false false R25.htm 2120100 - Disclosure - CAPITAL STOCK Sheet http://www.cmc.com/role/CapitalStock CAPITAL STOCK Notes 25 false false R26.htm 2121100 - Disclosure - EMPLOYEES' RETIREMENT PLANS Sheet http://www.cmc.com/role/EmployeesRetirementPlans EMPLOYEES' RETIREMENT PLANS Notes 26 false false R27.htm 2122100 - Disclosure - COMMITMENTS AND CONTINGENCIES Sheet http://www.cmc.com/role/CommitmentsAndContingencies COMMITMENTS AND CONTINGENCIES Notes 27 false false R28.htm 2123100 - Disclosure - EARNINGS PER SHARE Sheet http://www.cmc.com/role/EarningsPerShare EARNINGS PER SHARE Notes 28 false false R29.htm 2124100 - Disclosure - ACCRUED EXPENSES AND OTHER PAYABLES Sheet http://www.cmc.com/role/AccruedExpensesAndOtherPayables ACCRUED EXPENSES AND OTHER PAYABLES Notes 29 false false R30.htm 2126100 - Disclosure - BUSINESS SEGMENTS Sheet http://www.cmc.com/role/BusinessSegments BUSINESS SEGMENTS Notes 30 false false R31.htm 2127100 - Disclosure - QUARTERLY FINANCIAL DATA (UNAUDITED) Sheet http://www.cmc.com/role/QuarterlyFinancialDataUnaudited QUARTERLY FINANCIAL DATA (UNAUDITED) Notes 31 false false R32.htm 2130100 - Disclosure - SCHEDULE II ??? VALUATION AND QUALIFYING ACCOUNTS AND RESERVES Sheet http://www.cmc.com/role/ScheduleIiValuationAndQualifyingAccountsAndReserves SCHEDULE II ??? VALUATION AND QUALIFYING ACCOUNTS AND RESERVES Notes 32 false false R33.htm 2202201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Sheet http://www.cmc.com/role/SummaryOfSignificantAccountingPoliciesPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Policies 33 false false R34.htm 2302302 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Sheet http://www.cmc.com/role/SummaryOfSignificantAccountingPoliciesTables SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Tables http://www.cmc.com/role/SummaryOfSignificantAccountingPolicies 34 false false R35.htm 2304301 - Disclosure - CHANGES IN BUSINESS (Tables) Sheet http://www.cmc.com/role/ChangesInBusinessTables CHANGES IN BUSINESS (Tables) Tables http://www.cmc.com/role/ChangesInBusiness 35 false false R36.htm 2306301 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables) Sheet http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLossTables ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables) Tables http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLoss 36 false false R37.htm 2307301 - Disclosure - SALES OF ACCOUNTS RECEIVABLE (Activity of the Deferred Purchase Price Receivables) (Tables) Sheet http://www.cmc.com/role/SalesOfAccountsReceivableActivityOfDeferredPurchasePriceReceivablesTables SALES OF ACCOUNTS RECEIVABLE (Activity of the Deferred Purchase Price Receivables) (Tables) Tables http://www.cmc.com/role/SalesOfAccountsReceivable 37 false false R38.htm 2309301 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables) Sheet http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsTables GOODWILL AND OTHER INTANGIBLE ASSETS (Tables) Tables http://www.cmc.com/role/GoodwillAndOtherIntangibleAssets 38 false false R39.htm 2313301 - Disclosure - CREDIT ARRANGEMENTS (Tables) Sheet http://www.cmc.com/role/CreditArrangementsTables CREDIT ARRANGEMENTS (Tables) Tables http://www.cmc.com/role/CreditArrangements 39 false false R40.htm 2314301 - Disclosure - NEW MARKETS TAX CREDIT TRANSACTIONS New Markets Tax Credit Transactions (Tables) Sheet http://www.cmc.com/role/NewMarketsTaxCreditTransactionsNewMarketsTaxCreditTransactionsTables NEW MARKETS TAX CREDIT TRANSACTIONS New Markets Tax Credit Transactions (Tables) Tables 40 false false R41.htm 2315301 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Tables) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementTables DERIVATIVES AND RISK MANAGEMENT (Tables) Tables http://www.cmc.com/role/DerivativesAndRiskManagement 41 false false R42.htm 2316301 - Disclosure - FAIR VALUE (Tables) Sheet http://www.cmc.com/role/FairValueTables FAIR VALUE (Tables) Tables http://www.cmc.com/role/FairValue 42 false false R43.htm 2317301 - Disclosure - INCOME TAX (Tables) Sheet http://www.cmc.com/role/IncomeTaxTables INCOME TAX (Tables) Tables http://www.cmc.com/role/IncomeTax 43 false false R44.htm 2318301 - Disclosure - STOCK-BASED COMPENSATION PLANS (Tables) Sheet http://www.cmc.com/role/StockBasedCompensationPlansTables STOCK-BASED COMPENSATION PLANS (Tables) Tables http://www.cmc.com/role/StockBasedCompensationPlans 44 false false R45.htm 2322301 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables) Sheet http://www.cmc.com/role/CommitmentsAndContingenciesTables COMMITMENTS AND CONTINGENCIES (Tables) Tables http://www.cmc.com/role/CommitmentsAndContingencies 45 false false R46.htm 2323301 - Disclosure - EARNINGS PER SHARE (Tables) Sheet http://www.cmc.com/role/EarningsPerShareTables EARNINGS PER SHARE (Tables) Tables http://www.cmc.com/role/EarningsPerShare 46 false false R47.htm 2324301 - Disclosure - ACCRUED EXPENSES AND OTHER PAYABLES (Tables) Sheet http://www.cmc.com/role/AccruedExpensesAndOtherPayablesTables ACCRUED EXPENSES AND OTHER PAYABLES (Tables) Tables http://www.cmc.com/role/AccruedExpensesAndOtherPayables 47 false false R48.htm 2326301 - Disclosure - BUSINESS SEGMENTS (Tables) Sheet http://www.cmc.com/role/BusinessSegmentsTables BUSINESS SEGMENTS (Tables) Tables http://www.cmc.com/role/BusinessSegments 48 false false R49.htm 2327301 - Disclosure - QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables) Sheet http://www.cmc.com/role/QuarterlyFinancialDataUnauditedTables QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables) Tables http://www.cmc.com/role/QuarterlyFinancialDataUnaudited 49 false false R50.htm 2401401 - Disclosure - NATURE OF OPERATIONS (Narrative) (Details) Sheet http://www.cmc.com/role/NatureOfOperationsNarrativeDetails NATURE OF OPERATIONS (Narrative) (Details) Details http://www.cmc.com/role/NatureOfOperations 50 false false R51.htm 2402403 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) Sheet http://www.cmc.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) Details http://www.cmc.com/role/SummaryOfSignificantAccountingPoliciesTables 51 false false R52.htm 2402404 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Estimated Useful Lives of Property, Plant and Equipment) (Details) Sheet http://www.cmc.com/role/SummaryOfSignificantAccountingPoliciesEstimatedUsefulLivesOfPropertyPlantAndEquipmentDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Estimated Useful Lives of Property, Plant and Equipment) (Details) Details http://www.cmc.com/role/SummaryOfSignificantAccountingPoliciesTables 52 false false R53.htm 2404402 - Disclosure - CHANGES IN BUSINESS (Narrative) (Details) Sheet http://www.cmc.com/role/ChangesInBusinessNarrativeDetails CHANGES IN BUSINESS (Narrative) (Details) Details http://www.cmc.com/role/ChangesInBusinessTables 53 false false R54.htm 2404403 - Disclosure - CHANGES IN BUSINESS (Financial Information for Discontinued Operations) (Details) Sheet http://www.cmc.com/role/ChangesInBusinessFinancialInformationForDiscontinuedOperationsDetails CHANGES IN BUSINESS (Financial Information for Discontinued Operations) (Details) Details http://www.cmc.com/role/ChangesInBusinessTables 54 false false R55.htm 2404404 - Disclosure - CHANGES IN BUSINESS (Businesses Held for Sale) (Details) Sheet http://www.cmc.com/role/ChangesInBusinessBusinessesHeldForSaleDetails CHANGES IN BUSINESS (Businesses Held for Sale) (Details) Details http://www.cmc.com/role/ChangesInBusinessTables 55 false false R56.htm 2406402 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI by Components) (Details) Sheet http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLossAociByComponentsDetails ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI by Components) (Details) Details http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLossTables 56 false false R57.htm 2406403 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Reclassification out of accumulated other comprehensive income (loss)) (Details) Sheet http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLossReclassificationOutOfAccumulatedOtherComprehensiveIncomeLossDetails ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Reclassification out of accumulated other comprehensive income (loss)) (Details) Details http://www.cmc.com/role/AccumulatedOtherComprehensiveIncomeLossTables 57 false false R58.htm 2407402 - Disclosure - SALES OF ACCOUNTS RECEIVABLE (Narrative) (Details) Sheet http://www.cmc.com/role/SalesOfAccountsReceivableNarrativeDetails SALES OF ACCOUNTS RECEIVABLE (Narrative) (Details) Details http://www.cmc.com/role/SalesOfAccountsReceivableActivityOfDeferredPurchasePriceReceivablesTables 58 false false R59.htm 2407403 - Disclosure - SALES OF ACCOUNTS RECEIVABLE (Activity of the Deferred Purchase Price Receivables) (Details) Sheet http://www.cmc.com/role/SalesOfAccountsReceivableActivityOfDeferredPurchasePriceReceivablesDetails SALES OF ACCOUNTS RECEIVABLE (Activity of the Deferred Purchase Price Receivables) (Details) Details http://www.cmc.com/role/SalesOfAccountsReceivableActivityOfDeferredPurchasePriceReceivablesTables 59 false false R60.htm 2408401 - Disclosure - INVENTORIES (Narrative) (Details) Sheet http://www.cmc.com/role/InventoriesNarrativeDetails INVENTORIES (Narrative) (Details) Details http://www.cmc.com/role/Inventories 60 false false R61.htm 2409402 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Narrative) (Details) Sheet http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails GOODWILL AND OTHER INTANGIBLE ASSETS (Narrative) (Details) Details http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsTables 61 false false R62.htm 2409403 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Changes in the Carrying Amount of Goodwill) (Details) Sheet http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsChangesInCarryingAmountOfGoodwillDetails GOODWILL AND OTHER INTANGIBLE ASSETS (Changes in the Carrying Amount of Goodwill) (Details) Details http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsTables 62 false false R63.htm 2409404 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Intangible Assets) (Details) Sheet http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsIntangibleAssetsDetails GOODWILL AND OTHER INTANGIBLE ASSETS (Intangible Assets) (Details) Details http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsTables 63 false false R64.htm 2409405 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Estimated Future Amortization Expense) (Details) Sheet http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsEstimatedFutureAmortizationExpenseDetails GOODWILL AND OTHER INTANGIBLE ASSETS (Estimated Future Amortization Expense) (Details) Details http://www.cmc.com/role/GoodwillAndOtherIntangibleAssetsTables 64 false false R65.htm 2410401 - Disclosure - LONG-LIVED ASSET IMPAIRMENTS Long-lived Asset Impairments (Details) Sheet http://www.cmc.com/role/LongLivedAssetImpairmentsLongLivedAssetImpairmentsDetails LONG-LIVED ASSET IMPAIRMENTS Long-lived Asset Impairments (Details) Details 65 false false R66.htm 2411401 - Disclosure - EXIT COSTS (Narrative) (Details) Sheet http://www.cmc.com/role/ExitCostsNarrativeDetails EXIT COSTS (Narrative) (Details) Details http://www.cmc.com/role/ExitCosts 66 false false R67.htm 2413402 - Disclosure - CREDIT ARRANGEMENTS (Long-term Debt) (Details) Sheet http://www.cmc.com/role/CreditArrangementsLongTermDebtDetails CREDIT ARRANGEMENTS (Long-term Debt) (Details) Details http://www.cmc.com/role/CreditArrangementsTables 67 false false R68.htm 2413403 - Disclosure - CREDIT ARRANGEMENTS (Narrative) (Details) Sheet http://www.cmc.com/role/CreditArrangementsNarrativeDetails CREDIT ARRANGEMENTS (Narrative) (Details) Details http://www.cmc.com/role/CreditArrangementsTables 68 false false R69.htm 2413404 - Disclosure - CREDIT ARRANGEMENTS (Scheduled Maturities of Long-term Debt) (Details) Sheet http://www.cmc.com/role/CreditArrangementsScheduledMaturitiesOfLongTermDebtDetails CREDIT ARRANGEMENTS (Scheduled Maturities of Long-term Debt) (Details) Details http://www.cmc.com/role/CreditArrangementsTables 69 false false R70.htm 2414402 - Disclosure - NEW MARKETS TAX CREDIT TRANSACTIONS (Details) Sheet http://www.cmc.com/role/NewMarketsTaxCreditTransactionsDetails NEW MARKETS TAX CREDIT TRANSACTIONS (Details) Details http://www.cmc.com/role/NewMarketsTaxCreditTransactionsNewMarketsTaxCreditTransactionsTables 70 false false R71.htm 2415402 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Narrative) (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementNarrativeDetails DERIVATIVES AND RISK MANAGEMENT (Narrative) (Details) Details http://www.cmc.com/role/DerivativesAndRiskManagementTables 71 false false R72.htm 2415403 - Disclosure - DERIVATIVES AND RISK MANAGEMENT - Commodity Contract Commitments (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementCommodityContractCommitmentsDetails DERIVATIVES AND RISK MANAGEMENT - Commodity Contract Commitments (Details) Details 72 false false R73.htm 2415404 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Derivatives Not Designated as Hedging Instruments) (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementDerivativesNotDesignatedAsHedgingInstrumentsDetails DERIVATIVES AND RISK MANAGEMENT (Derivatives Not Designated as Hedging Instruments) (Details) Details http://www.cmc.com/role/DerivativesAndRiskManagementTables 73 false false R74.htm 2415405 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Derivatives Designated as Fair Value Hedging Instruments) (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementDerivativesDesignatedAsFairValueHedgingInstrumentsDetails DERIVATIVES AND RISK MANAGEMENT (Derivatives Designated as Fair Value Hedging Instruments) (Details) Details http://www.cmc.com/role/DerivativesAndRiskManagementTables 74 false false R75.htm 2415406 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Effective Portion of Derivatives Designated as Cash Flow Hedging Instruments Recognized in Accumulated Other Comprehensive Income (Loss)) (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementEffectivePortionOfDerivativesDesignatedAsCashFlowHedgingInstrumentsRecognizedInAccumulatedOtherComprehensiveIncomeLossDetails DERIVATIVES AND RISK MANAGEMENT (Effective Portion of Derivatives Designated as Cash Flow Hedging Instruments Recognized in Accumulated Other Comprehensive Income (Loss)) (Details) Details http://www.cmc.com/role/DerivativesAndRiskManagementTables 75 false false R76.htm 2415407 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Derivative Assets) (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementDerivativeAssetsDetails DERIVATIVES AND RISK MANAGEMENT (Derivative Assets) (Details) Details http://www.cmc.com/role/DerivativesAndRiskManagementTables 76 false false R77.htm 2415408 - Disclosure - DERIVATIVES AND RISK MANAGEMENT (Derivative Liabilities) (Details) Sheet http://www.cmc.com/role/DerivativesAndRiskManagementDerivativeLiabilitiesDetails DERIVATIVES AND RISK MANAGEMENT (Derivative Liabilities) (Details) Details http://www.cmc.com/role/DerivativesAndRiskManagementTables 77 false false R78.htm 2416402 - Disclosure - FAIR VALUE (Narrative) (Details) Sheet http://www.cmc.com/role/FairValueNarrativeDetails FAIR VALUE (Narrative) (Details) Details http://www.cmc.com/role/FairValueTables 78 false false R79.htm 2416403 - Disclosure - FAIR VALUE (Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis) (Details) Sheet http://www.cmc.com/role/FairValueFinancialAssetsAndFinancialLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails FAIR VALUE (Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis) (Details) Details http://www.cmc.com/role/FairValueTables 79 false false R80.htm 2416404 - Disclosure - FAIR VALUE FAIR VALUE (Financial Assets and Liabilities Not Required to Be Measured at Fair Value) (Details) Sheet http://www.cmc.com/role/FairValueFairValueFinancialAssetsAndLiabilitiesNotRequiredToBeMeasuredAtFairValueDetails FAIR VALUE FAIR VALUE (Financial Assets and Liabilities Not Required to Be Measured at Fair Value) (Details) Details 80 false false R81.htm 2417402 - Disclosure - INCOME TAX (Narrative) (Details) Sheet http://www.cmc.com/role/IncomeTaxNarrativeDetails INCOME TAX (Narrative) (Details) Details http://www.cmc.com/role/IncomeTaxTables 81 false false R82.htm 2417403 - Disclosure - INCOME TAX (Components of Earnings from Continuing Operations before Income Taxes) (Details) Sheet http://www.cmc.com/role/IncomeTaxComponentsOfEarningsFromContinuingOperationsBeforeIncomeTaxesDetails INCOME TAX (Components of Earnings from Continuing Operations before Income Taxes) (Details) Details http://www.cmc.com/role/IncomeTaxTables 82 false false R83.htm 2417404 - Disclosure - INCOME TAX (Income Taxes Included in the Consolidated Statements of Operations) (Details) Sheet http://www.cmc.com/role/IncomeTaxIncomeTaxesIncludedInConsolidatedStatementsOfOperationsDetails INCOME TAX (Income Taxes Included in the Consolidated Statements of Operations) (Details) Details http://www.cmc.com/role/IncomeTaxTables 83 false false R84.htm 2417405 - Disclosure - INCOME TAX (Reconciliation of Federal Statutory Rate to Effective Tax Rate from Continuing Operations) (Details) Sheet http://www.cmc.com/role/IncomeTaxReconciliationOfFederalStatutoryRateToEffectiveTaxRateFromContinuingOperationsDetails INCOME TAX (Reconciliation of Federal Statutory Rate to Effective Tax Rate from Continuing Operations) (Details) Details http://www.cmc.com/role/IncomeTaxTables 84 false false R85.htm 2417406 - Disclosure - INCOME TAX (Deferred Tax Assets and Liabilities) (Details) Sheet http://www.cmc.com/role/IncomeTaxDeferredTaxAssetsAndLiabilitiesDetails INCOME TAX (Deferred Tax Assets and Liabilities) (Details) Details http://www.cmc.com/role/IncomeTaxTables 85 false false R86.htm 2417407 - Disclosure - INCOME TAX (Unrecognized Tax Benefits) (Details) Sheet http://www.cmc.com/role/IncomeTaxUnrecognizedTaxBenefitsDetails INCOME TAX (Unrecognized Tax Benefits) (Details) Details http://www.cmc.com/role/IncomeTaxTables 86 false false R87.htm 2418402 - Disclosure - STOCK-BASED COMPENSATION PLANS (Stock-Based Awards Granted) (Details) Sheet http://www.cmc.com/role/StockBasedCompensationPlansStockBasedAwardsGrantedDetails STOCK-BASED COMPENSATION PLANS (Stock-Based Awards Granted) (Details) Details http://www.cmc.com/role/StockBasedCompensationPlansTables 87 false false R88.htm 2418403 - Disclosure - STOCK-BASED COMPENSATION PLANS (Narrative) (Details) Sheet http://www.cmc.com/role/StockBasedCompensationPlansNarrativeDetails STOCK-BASED COMPENSATION PLANS (Narrative) (Details) Details http://www.cmc.com/role/StockBasedCompensationPlansTables 88 false false R89.htm 2418404 - Disclosure - STOCK-BASED COMPENSATION PLANS (Restricted Stock Awards and Performance Stock Units Excluding the Cash Component) (Details) Sheet http://www.cmc.com/role/StockBasedCompensationPlansRestrictedStockAwardsAndPerformanceStockUnitsExcludingCashComponentDetails STOCK-BASED COMPENSATION PLANS (Restricted Stock Awards and Performance Stock Units Excluding the Cash Component) (Details) Details http://www.cmc.com/role/StockBasedCompensationPlansTables 89 false false R90.htm 2418405 - Disclosure - STOCK-BASED COMPENSATION PLANS (Combined Activity for Stock Appreciation Rights and Stock Options Excluding the Cash Component) (Details) Sheet http://www.cmc.com/role/StockBasedCompensationPlansCombinedActivityForStockAppreciationRightsAndStockOptionsExcludingCashComponentDetails STOCK-BASED COMPENSATION PLANS (Combined Activity for Stock Appreciation Rights and Stock Options Excluding the Cash Component) (Details) Details http://www.cmc.com/role/StockBasedCompensationPlansTables 90 false false R91.htm 2418406 - Disclosure - STOCK-BASED COMPENSATION PLANS (Information Related To Stock Appreciation Rights And Stock Options) (Details) Sheet http://www.cmc.com/role/StockBasedCompensationPlansInformationRelatedToStockAppreciationRightsAndStockOptionsDetails STOCK-BASED COMPENSATION PLANS (Information Related To Stock Appreciation Rights And Stock Options) (Details) Details http://www.cmc.com/role/StockBasedCompensationPlansTables 91 false false R92.htm 2418407 - Disclosure - STOCK-BASED COMPENSATION PLANS (Yearly Activity of Stock Purchase Plan) (Details) Sheet http://www.cmc.com/role/StockBasedCompensationPlansYearlyActivityOfStockPurchasePlanDetails STOCK-BASED COMPENSATION PLANS (Yearly Activity of Stock Purchase Plan) (Details) Details http://www.cmc.com/role/StockBasedCompensationPlansTables 92 false false R93.htm 2420401 - Disclosure - CAPITAL STOCK (Narrative) (Details) Sheet http://www.cmc.com/role/CapitalStockNarrativeDetails CAPITAL STOCK (Narrative) (Details) Details http://www.cmc.com/role/CapitalStock 93 false false R94.htm 2421401 - Disclosure - EMPLOYEES' RETIREMENT PLANS (Narrative) (Details) Sheet http://www.cmc.com/role/EmployeesRetirementPlansNarrativeDetails EMPLOYEES' RETIREMENT PLANS (Narrative) (Details) Details http://www.cmc.com/role/EmployeesRetirementPlans 94 false false R95.htm 2422402 - Disclosure - COMMITMENTS AND CONTINGENCIES (Minimum Lease Commitments Payable for Noncancelable Operating Leases) (Details) Sheet http://www.cmc.com/role/CommitmentsAndContingenciesMinimumLeaseCommitmentsPayableForNoncancelableOperatingLeasesDetails COMMITMENTS AND CONTINGENCIES (Minimum Lease Commitments Payable for Noncancelable Operating Leases) (Details) Details http://www.cmc.com/role/CommitmentsAndContingenciesTables 95 false false R96.htm 2422403 - Disclosure - COMMITMENTS AND CONTINGENCIES (Narrative) (Details) Sheet http://www.cmc.com/role/CommitmentsAndContingenciesNarrativeDetails COMMITMENTS AND CONTINGENCIES (Narrative) (Details) Details http://www.cmc.com/role/CommitmentsAndContingenciesTables 96 false false R97.htm 2423402 - Disclosure - EARNINGS PER SHARE (Calculations of Basic and Diluted Earnings Per Share) (Details) Sheet http://www.cmc.com/role/EarningsPerShareCalculationsOfBasicAndDilutedEarningsPerShareDetails EARNINGS PER SHARE (Calculations of Basic and Diluted Earnings Per Share) (Details) Details http://www.cmc.com/role/EarningsPerShareTables 97 false false R98.htm 2424402 - Disclosure - ACCRUED EXPENSES AND OTHER PAYABLES (Details) Sheet http://www.cmc.com/role/AccruedExpensesAndOtherPayablesDetails ACCRUED EXPENSES AND OTHER PAYABLES (Details) Details http://www.cmc.com/role/AccruedExpensesAndOtherPayablesTables 98 false false R99.htm 2426402 - Disclosure - BUSINESS SEGMENTS (Narrative) (Details) Sheet http://www.cmc.com/role/BusinessSegmentsNarrativeDetails BUSINESS SEGMENTS (Narrative) (Details) Details http://www.cmc.com/role/BusinessSegmentsTables 99 false false R100.htm 2426403 - Disclosure - BUSINESS SEGMENTS (Summary of Certain Financial Information from Continuing Operations by Reportable Segment) (Details) Sheet http://www.cmc.com/role/BusinessSegmentsSummaryOfCertainFinancialInformationFromContinuingOperationsByReportableSegmentDetails BUSINESS SEGMENTS (Summary of Certain Financial Information from Continuing Operations by Reportable Segment) (Details) Details http://www.cmc.com/role/BusinessSegmentsTables 100 false false R101.htm 2426404 - Disclosure - BUSINESS SEGMENTS (Reconciliations of Earnings from Continuing Operations to Adjusted Operating Profit) (Details) Sheet http://www.cmc.com/role/BusinessSegmentsReconciliationsOfEarningsFromContinuingOperationsToAdjustedOperatingProfitDetails BUSINESS SEGMENTS (Reconciliations of Earnings from Continuing Operations to Adjusted Operating Profit) (Details) Details http://www.cmc.com/role/BusinessSegmentsTables 101 false false R102.htm 2426405 - Disclosure - BUSINESS SEGMENTS (External Net Sales from Continuing Operations by Major Product) (Details) Sheet http://www.cmc.com/role/BusinessSegmentsExternalNetSalesFromContinuingOperationsByMajorProductDetails BUSINESS SEGMENTS (External Net Sales from Continuing Operations by Major Product) (Details) Details http://www.cmc.com/role/BusinessSegmentsTables 102 false false R103.htm 2426406 - Disclosure - BUSINESS SEGMENTS (External Net Sales from Continuing Operations by Geographic Area) (Details) Sheet http://www.cmc.com/role/BusinessSegmentsExternalNetSalesFromContinuingOperationsByGeographicAreaDetails BUSINESS SEGMENTS (External Net Sales from Continuing Operations by Geographic Area) (Details) Details http://www.cmc.com/role/BusinessSegmentsTables 103 false false R104.htm 2426407 - Disclosure - BUSINESS SEGMENTS (Long-Lived Assets by Geographic Area) (Details) Sheet http://www.cmc.com/role/BusinessSegmentsLongLivedAssetsByGeographicAreaDetails BUSINESS SEGMENTS (Long-Lived Assets by Geographic Area) (Details) Details http://www.cmc.com/role/BusinessSegmentsTables 104 false false R105.htm 2427402 - Disclosure - QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) Sheet http://www.cmc.com/role/QuarterlyFinancialDataUnauditedDetails QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) Details http://www.cmc.com/role/QuarterlyFinancialDataUnauditedTables 105 false false R106.htm 2430401 - Disclosure - SCHEDULE II ??? VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) Sheet http://www.cmc.com/role/ScheduleIiValuationAndQualifyingAccountsAndReservesDetails SCHEDULE II ??? VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) Details http://www.cmc.com/role/ScheduleIiValuationAndQualifyingAccountsAndReserves 106 false false R107.htm 2430402 - Disclosure - SCHEDULE II ??? VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Narrative) (Details) Sheet http://www.cmc.com/role/ScheduleIiValuationAndQualifyingAccountsAndReservesNarrativeDetails SCHEDULE II ??? VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Narrative) (Details) Details http://www.cmc.com/role/ScheduleIiValuationAndQualifyingAccountsAndReserves 107 false false All Reports Book All Reports cmc-20180831.xml cmc-20180831.xsd cmc-20180831_cal.xml cmc-20180831_def.xml cmc-20180831_lab.xml cmc-20180831_pre.xml http://xbrl.sec.gov/country/2017-01-31 http://fasb.org/us-gaap/2018-01-31 http://xbrl.sec.gov/dei/2018-01-31 http://xbrl.sec.gov/invest/2013-01-31 http://fasb.org/srt/2018-01-31 true true