| Cover page | Nov. 03, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 3, 2020 |
| Entity Registrant Name | LAM RESEARCH CORPORATION |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 0-12933 |
| Entity Tax Identification Number | 94-2634797 |
| Entity Address, Address Line One | 4650 Cushing Parkway |
| Entity Address, City or Town | Fremont |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94538 |
| City Area Code | 510 |
| Local Phone Number | 572-0200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, Par Value $0.001 Per Share |
| Trading Symbol | LRCX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0000707549 |
