BASIS OF PRESENTATION (Policies)	6 Months Ended
BASIS OF PRESENTATION (Policies)	Dec. 26, 2021
Accounting Policies [Abstract]
Consolidation	The condensed consolidated financial statements include the accounts of Lam Research and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Fiscal Period	The Company’s reporting period is a 52/53-week fiscal year. The Company’s current fiscal year will end June 26, 2022 and includes 52 weeks.
Recent Accounting Pronouncements	Recently Adopted The Company did not adopt any new accounting standards during the first quarter of fiscal year 2022 that had a material impact on the Company’s Condensed Consolidated Financial Statements. Updates Not Yet Adopted or Effective In November 2021, the Financial Accounting Standards Board issued Accounting Standards Update 2021-10, “Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance,” which requires business entities to make annual disclosures, including the nature of transactions and the related accounting policy used to account for the transactions, significant terms and conditions, and line items affected, about transactions with a government (including government assistance) that are accounted for by analogizing to a grant or contribution accounting model. The guidance is effective for financial statements issued for annual periods beginning after December 15, 2021, with early adoption permitted. The Company is required to adopt this standard in the first quarter of fiscal year 2023 for the annual reporting period ending June 25, 2023. The guidance may be applied either prospectively to all in-scope transactions at the date of initial application or retrospectively. The Company is currently in the process of evaluating the impact of adoption on its Consolidated Financial Statements.
Inventories	Inventories are stated at the lower of cost (first-in, first-out method) or net realizable value. System shipments to customers in Japan, for which title does not transfer until customer acceptance, are classified as finished goods inventory and carried at cost until title transfers.
Warranties	The Company provides standard warranties on its systems. The liability amount is based on actual historical warranty spending activity by type of system, customer, and geographic region, modified for any known differences such as the impact of system reliability improvements.

Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost.