EMPLOYEE BENEFIT PLANS AND OTHER POST-RETIREMENT BENEFITS - Other Plans - Conagra's Defined Contribution Plan (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2020	May 26, 2019	May 27, 2018
EMPLOYEE BENEFIT PLANS AND OTHER POST-RETIREMENT BENEFITS
Matching percentage (as a percent)	100.00%
Employee's contribution election (as a percent)	6.00%
Employee compensation (as a percent)	3.00%
Plan matching contribution, vesting period	5 years
Plan matching contribution, vesting percentage (as a percent)	20.00%
Plan matching contribution	$ 28.7	$ 21.3	$ 13.9

Percentage employer matches of the employee's percentage contribution matched of the employee compensation.

No definition available.

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Namespace Prefix:	lw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage employer matches of the employee's percentage contribution matched of the employee's contribution election .

+ References

No definition available.

+ Details

Name:	lw_DefinedContributionPlanEmployerMatchingContributionPercentOfMatchEmployeesContributionElection
Namespace Prefix:	lw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of employer's matching contributions to a defined contribution plan that vests.

+ References

No definition available.

+ Details

Name:	lw_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPeriod
Namespace Prefix:	lw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration