EMPLOYEE BENEFIT PLANS AND OTHER POST-RETIREMENT BENEFITS - Other Plans - Conagra's Defined Contribution Plan (Details) $ in Millions	12 Months Ended
May 28, 2017 USD ($)
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, vesting percentage, after five years (as a percent)	100.00%
Plan matching contribution	$ 6.0

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

No definition available.

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

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

No definition available.

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

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

No definition available.

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

Percentage of employer's matching contributions to a defined contribution plan vested after five years.

No definition available.

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

No definition available.

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

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

No definition available.

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

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

No definition available.

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

Maximum amount the employee may contribute to a defined contribution plan.

No definition available.

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