XML 180 R99.htm IDEA: XBRL DOCUMENT
v3.20.2

EMPLOYEES' RETIREMENT PLANS (Weighted-average Assumptions) (Details) - USD ($) | 12 Months Ended
--- | ---
Aug. 31, 2020 | Aug. 31, 2019
Defined Benefit Plan Obligations |  |
Effective discount rate for benefit obligations | 2.80% | 3.20%
Net Periodic Benefit Cost |  |
Effective rate for interest on benefit obligations | 2.80% | 4.30%
Effective rate for service cost | 3.30% | 4.70%
Expected long-term rate of return | 6.00% | 6.00%
Effective rate for interest on benefit obligations, remeasured | 2.90% |
Effective rate for service cost, remeasured | 3.50% |
Expected long-term rate of return on plan assets for 2020 | 5.00% |
Expected future employer contributions in fiscal 2021 | $ 0 |

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Effective Rate for Service Cost, Remeasured + References No definition available. + Details
Name: | cmc_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostEffectiveRateForServiceCostRemeasured
Namespace Prefix: | cmc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Effective Rate for Service Cost + References No definition available. + Details
Name: | cmc_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostEffectiveRateforServiceCost
Namespace Prefix: | cmc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets, Year Two + References No definition available. + Details
Name: | cmc_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongtermRateofReturnonPlanAssetsYearTwo
Namespace Prefix: | cmc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Effective Interest Rate on Benefit Obligations, Remeasured + References No definition available. + Details
Name: | cmc_DefinedBenefitPlanEffectiveInterestRateOnBenefitObligationsRemeasured
Namespace Prefix: | cmc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Effective Interest Rate on Benefit Obligations + References No definition available. + Details
Name: | cmc_DefinedBenefitPlanEffectiveInterestRateonBenefitObligations
Namespace Prefix: | cmc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2919-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4587-114921 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration