Hedged Debt

No definition available.

Name:	cnm_HedgedDebt
Namespace Prefix:	cnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payments For Settlement Of Derivatives

+ References

No definition available.

+ Details

Name:	cnm_PaymentsForSettlementOfDerivatives
Namespace Prefix:	cnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair value of all asset derivatives designated as cash flow hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
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-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
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-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Topic 815
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeLiabilityNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

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

- Definition

The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cnm_InterestRateSwapOneMember
Namespace Prefix:
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- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cnm_InterestRateSwapTwoMember
Namespace Prefix:
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Balance Type:
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- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
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- Details

Name:	us-gaap_DebtInstrumentAxis=cnm_SeniorTermLoanDueAugust2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LoansPayableMember
Namespace Prefix:
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- Details

Name:	us-gaap_DebtInstrumentAxis=cnm_SeniorTermLoanDueJuly2028Member
Namespace Prefix:
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- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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Debt - Interest Rate Swaps Narrative (Details) - USD ($)			6 Months Ended	12 Months Ended
	Jan. 30, 2022	Jul. 27, 2021	Jan. 30, 2022	Jan. 30, 2022	Jan. 31, 2021	Feb. 02, 2020	Jul. 27, 2025	Jul. 27, 2024	Jul. 27, 2023	Feb. 28, 2018
Derivative [Line Items]
Settlement of interest rate swap				$ 5,000,000	$ 0	$ 0
Interest rate swap 1 \| Cash flow
Derivative [Line Items]
Fixed interest rate (percent)										2.725%
Notional amount										$ 500,000,000
Settlement of interest rate swap		$ 5,000,000
Interest rate swap 2
Derivative [Line Items]
Fair value of this cash flow interest rate swap asset	$ 31,000,000		$ 31,000,000	$ 31,000,000
Interest rate swap 2 \| Cash flow
Derivative [Line Items]
Fixed interest rate (percent)	0.74%	0.74%	0.74%	0.74%
Notional amount		$ 1,000,000,000
Interest rate swap 2 \| Cash flow \| Forecast
Derivative [Line Items]
Notional amount							$ 700,000,000	$ 800,000,000	$ 900,000,000
Prior Term Loan Facility \| Term loan
Derivative [Line Items]
Repayment of senior debt		$ 1,258,000,000
Senior Term Loan Facility \| Term loan
Derivative [Line Items]
Effective fixed rate (percent)	3.24%		3.24%	3.24%
Hedged borrowings	$ 1,000,000,000		$ 1,000,000,000	$ 1,000,000,000
Senior Term Loan Facility \| Term loan \| LIBOR
Derivative [Line Items]
Applicable margin (percent)	2.50%		2.50%