This represents disposal price of a business unit or asset during divestiture.

No definition available.

Name:	cmc_BusinessDivestitureDisposalPrice
Namespace Prefix:	cmc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Disposal Group, Including Discontinued Operations, Impairment

+ References

No definition available.

+ Details

Name:	cmc_DisposalGroupIncludingDiscontinuedOperationsImpairment
Namespace Prefix:	cmc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

It represents escrow receivable related to business or asset disposal.

+ References

No definition available.

+ Details

Name:	cmc_Escrowreceivable
Namespace Prefix:	cmc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of foreign currency translation gain (loss) in the disposal group, including discontinued operation, recognized in the statement of income as a result of the sale or complete or substantially complete liquidation of an investment in a foreign entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 20
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64808268&loc=d3e32211-110900

+ Details

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=cmc_HowellMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

BUSINESSES HELD FOR SALE, DISCONTINUED OPERATIONS AND DISPOSITIONS (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	May 31, 2016	Nov. 30, 2013	Aug. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Non-recurring impairment charge	$ 15.8
Foreign currency translation loss	$ 13.5
Howell
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business divestiture disposal price		$ 58.5
Escrow receivable			$ 3.2