BASIS OF PRESENTATION (Policies)	9 Months Ended
BASIS OF PRESENTATION (Policies)	Mar. 29, 2026
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 28, 2026 and includes 52 weeks.
Recently Adopted or Effective	Recently Adopted or Effective The Company has not adopted any new accounting standards during the three and nine months ended March 29, 2026 that have a material impact on the Company’s Condensed Consolidated Financial Statements.
Inventories	Inventories are stated at the lower of cost or net realizable value using standard costs that approximate actual costs on a first-in, first-out basis.
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.