INVESTMENTS IN JOINT VENTURES - Consolidated Entity - Consideration Transferred (Details) - Lamb Weston BSW, LLC $ in Millions	Nov. 02, 2018 USD ($)
Consideration transferred
Call option	$ 65.0
Additional payment	$ 13.2

Variable Interest Entity, Call Option to Purchase Remaining Equity Interest, Seller Surrender Economic Rights Ahead of Acquisition Date, Amount

No definition available.

Name:	lw_VariableInterestEntityCallOptionToPurchaseRemainingEquityInterestSellerSurrenderEconomicRightsAheadOfAcquisitionDateAmount
Namespace Prefix:	lw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant