2.4.0.81097 - Disclosure - Pro Forma Results (Detail)truefalseIn Thousands, except Per Share data, unless otherwise specifiedfalse1falseUSDfalsefalse$eol_PE5807----1310-K0007_STD_364_20120624_0http://www.sec.gov/CIK0000707549duration2011-06-27T00:00:002012-06-24T00:00:00iso4217_USD_per_sharesDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instanceshares0iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falseUSDfalsefalse$eol_PE5807----1310-K0007_STD_364_20110626_0http://www.sec.gov/CIK0000707549duration2010-06-28T00:00:002011-06-26T00:00:00iso4217_USD_per_sharesDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instanceshares0iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true3lrcx_BusinessAcquisitionProFormaInformationLineItemslrcx_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse02false4us-gaap_BusinessAcquisitionsProFormaRevenueus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse38042520003804252USD$falsetruefalse2truefalsefalse47437970004743797USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463
false23false4us-gaap_BusinessAcquisitionsProFormaNetIncomeLossus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse152981000152981USD$falsetruefalse2truefalsefalse894864000894864USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463
false24false4us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasicus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse0.760.76USD$falsetruefalse2truefalsefalse4.344.34USD$falsetruefalsenum:perShareItemTypedecimalThe pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463
false35false4us-gaap_BusinessAcquisitionProFormaEarningsPerShareDilutedus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse0.740.74USD$falsetruefalse2truefalsefalse4.184.18USD$falsetruefalsenum:perShareItemTypedecimalThe pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463
false3falsePro Forma Results (Detail) (USD $)ThousandsUnKnownNoRoundingUnKnowntruefalsefalseSheethttp://www.lamresearch.com/taxonomy/role/DisclosureProFormaResults25
