Represents the aggregate amount of purchase price of ordinary shares under collaborative arrangements.

No definition available.

Name:	kr_CollaborativeArrangementsAggregatePurchasePriceOfOrdinaryShares
Namespace Prefix:	kr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of exclusivity fee to be paid and letter of credit under collaborative arrangements.

+ References

No definition available.

+ Details

Name:	kr_CollaborativeArrangementsExclusivityFeeToBePaidAndLetterOfCredit
Namespace Prefix:	kr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the number of ordinary shares purchased under collaborative arrangements.

+ References

No definition available.

+ Details

Name:	kr_CollaborativeArrangementsNumberOfOrdinarySharesPurchased
Namespace Prefix:	kr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of ordinary shares to be purchased under collaborative arrangements.

+ References

No definition available.

+ Details

Name:	kr_CollaborativeArrangementsNumberOfOrdinarySharesToBePurchased
Namespace Prefix:	kr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

No definition available.

+ Details

Name:	kr_EquitySecuritiesFvNi
Namespace Prefix:	kr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of realized gain from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

No definition available.

+ Details

Name:	kr_EquitySecuritiesFvNiRealizedGain
Namespace Prefix:	kr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

No definition available.

+ Details

Name:	kr_EquitySecuritiesFvNiUnrealizedGain
Namespace Prefix:	kr_
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

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

- Details

Name:	us-gaap_CounterpartyNameAxis=kr_OcadoInternationalHoldingsLimitedAndOcadoGroupPlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=kr_PartnershipFrameworkAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=kr_ShareSubscriptionAgreementMember
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MERGER AND PARTNERSHIP AGREEMENTS - Partnership Agreement (Details) - USD ($) shares in Millions, $ in Millions			3 Months Ended	4 Months Ended	6 Months Ended
	May 29, 2018	May 17, 2018	Aug. 18, 2018	May 26, 2018	Aug. 18, 2018
Arrangement
Unrealized gain on equity securities			$ 216		$ 252
Ocado
Arrangement
Unrealized gain on equity securities					252
Realized gain on equity securities					0
Ocado \| Other Assets
Arrangement
Fair value of equity securities			$ 645		$ 645
Partnership Framework Agreement \| Ocado
Arrangement
Exclusivity fee and letter of credit		$ 180
Share Subscription Agreement \| Ocado
Arrangement
Number of ordinary shares to be purchased		33.1
Aggregate purchase price		$ 243
Number of ordinary shares purchased	33.1		6.5	8.1