2.4.0.81093 - Disclosure - Consideration Transferred to Acquire Novellus (Parenthetical) (Detail)truefalsefalse1falsefalsefalseeol_PE5807----1310-K0007_STD_0_20120604_0_712653x734448http://www.sec.gov/CIK0000707549instant2012-06-04T00:00:000001-01-01T00:00:00pureStandardhttp://www.xbrl.org/2003/instancepure01false0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse1falsetruefalseeol_PE5807----1310-K0007_STD_0_20120604_0_712653x734448http://www.sec.gov/CIK0000707549instant2012-06-04T00:00:000001-01-01T00:00:00falsefalseNovellus Systems Incorporatedus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldilrcx_NovellusSystemsIncorporatedMemberus-gaap_BusinessAcquisitionAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse02true3us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse03false4lrcx_ConvertibleSharesExchangeRatiolrcx_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1.1251.125falsefalsefalsexbrli:decimalItemTypedecimalThe ratio by which Novellus Systems Inc. shares were converted to Lam Research Inc. shares as a result of the acquisition of Novellus.No definition available.false0falseConsideration Transferred to Acquire Novellus (Parenthetical) (Detail) (Novellus Systems Incorporated)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.lamresearch.com/taxonomy/role/DisclosureConsiderationTransferredToAcquireNovellusParenthetical13
