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Time period for cumulative operating cash flow and total share holder return of the Company's common stock relative to a select group of peer companies under the share based payment performance award conditions.

No definition available.

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Performance award settlement as a percentage of the target.

No definition available.

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Performance Share Target Grant

No definition available.

Name:	k_PerformanceShareTargetGrant
Namespace Prefix:	k_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Description of award terms as to the maximum number of shares that could actually be delivered under an award upon satisfaction of a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale, expressed as a percentage of the shares under the award.

No definition available.

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Period Type:	instant

Description of award terms as to the minimum number of shares that could actually be delivered under an award upon satisfaction of a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale, expressed as a percentage of the shares under the award.

No definition available.

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Data Type:	dtr-types:percentItemType
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Period Type:	instant

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Data Type:	dtr-types:perShareItemType
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Period Type:	instant

Amount of cash paid to settle liability for award under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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.

No definition available.

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Data Type:	xbrli:stringItemType
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Data Type:	na
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Name:	us-gaap_AwardDateAxis=k_TwentyNineteenAwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_AwardTypeAxis=k_TwentyTwentyOnePerformanceShareAwardMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_AwardTypeAxis=k_TwentyTwentyPerformanceShareAwardMember
Namespace Prefix:
Data Type:	na
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