STOCK-BASED COMPENSATION - Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Nov. 24, 2019	Nov. 25, 2018	Nov. 24, 2019	Nov. 25, 2018
Compensation expense
Stock-settled compensation expense	$ 7.2	$ 5.0	$ 12.6	$ 9.2
Cash-settled RSUs		1.6	1.0	3.7
Total compensation expense	7.2	6.6	13.6	12.9
Income tax benefit	(1.6)	(1.5)	(3.1)	(3.0)
Total compensation expense, net of tax benefit	5.6	5.1	10.5	9.9
Stock-settled restricted stock units
Compensation expense
Stock-settled compensation expense	3.5	2.7	6.3	4.9
Performance shares
Compensation expense
Stock-settled compensation expense	$ 3.7	2.2	6.2	4.1
Stock options
Compensation expense
Stock-settled compensation expense		$ 0.1	$ 0.1	$ 0.2

Allocated Share-based Compensation Expense, Cash-settled Restricted Stock Units

No definition available.

Name:	lw_AllocatedShareBasedCompensationExpenseCashSettledRestrictedStockUnits
Namespace Prefix:	lw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Allocated Share-based Compensation Expense, Stock-settled Compensation Expense

+ References

No definition available.

+ Details

Name:	lw_AllocatedShareBasedCompensationExpenseStockSettledCompensationExpense
Namespace Prefix:	lw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

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

- Definition

Amount, after tax, of expense for award under share-based payment arrangement.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

+ References

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 (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

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

- Details

Name:	us-gaap_AwardTypeAxis=lw_StockSettledRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: