Cash, Cash Equivalents, Short-Term Investments, Restricted Cash and Investments and Other Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2015	Jun. 29, 2014
Financial Instruments [Line Items]
Cost	$ 4,148,577lrcx_InvestmentsAmortizedCost	$ 3,228,743lrcx_InvestmentsAmortizedCost
Unrealized Gain	7,325lrcx_InvestmentsUnrealizedGain	6,551lrcx_InvestmentsUnrealizedGain
Unrealized (Loss)	(2,012)lrcx_InvestmentsUnrealizedLoss	(1,400)lrcx_InvestmentsUnrealizedLoss
Fair Value	4,153,890us-gaap_InvestmentsFairValueDisclosure	3,233,894us-gaap_InvestmentsFairValueDisclosure
Cash and Cash Equivalents	1,635,636	1,452,677
Short-Term Investments	2,313,495	1,612,967
Restricted Cash & Investments	164,300lrcx_RestrictedCashFairValueDisclosure	146,492lrcx_RestrictedCashFairValueDisclosure
Other Assets	40,459us-gaap_OtherAssetsFairValueDisclosure	21,758us-gaap_OtherAssetsFairValueDisclosure
Fair Value Level 1
Financial Instruments [Line Items]
Cost	1,708,223	1,532,030
Unrealized Gain	4,828	3,152
Unrealized (Loss)	(47)	(27)
Fair Value	1,713,004	1,535,155
Cash and Cash Equivalents	1,215,441	1,168,261
Short-Term Investments	299,335	204,549
Restricted Cash & Investments	157,769	140,587
Other Assets	40,459	21,758
Fair Value Level 2
Financial Instruments [Line Items]
Cost	2,013,628	1,411,682
Unrealized Gain	2,497	3,399
Unrealized (Loss)	(1,965)	(1,373)
Fair Value	2,014,160	1,413,708
Cash and Cash Equivalents		5,290
Short-Term Investments	2,014,160	1,408,418
Fair Value Level 2 \| Municipal Notes And Bonds
Financial Instruments [Line Items]
Cost	479,943	334,329
Unrealized Gain	716	1,108
Unrealized (Loss)	(51)	(4)
Fair Value	480,608	335,433
Cash and Cash Equivalents		5,290
Short-Term Investments	480,608	330,143
Fair Value Level 2 \| Corporate Notes And Bonds
Financial Instruments [Line Items]
Cost	1,228,757	874,540
Unrealized Gain	1,550	2,034
Unrealized (Loss)	(973)	(335)
Fair Value	1,229,334	876,239
Short-Term Investments	1,229,334	876,239
Cash
Financial Instruments [Line Items]
Cost	426,726	285,031
Fair Value	426,726	285,031
Cash and Cash Equivalents	420,195	279,126
Restricted Cash & Investments	6,531	5,905
Time Deposits \| Fair Value Level 1
Financial Instruments [Line Items]
Cost	132,549	132,549
Fair Value	132,549	132,549
Restricted Cash & Investments	132,549	132,549
Money Market Funds \| Fair Value Level 1
Financial Instruments [Line Items]
Cost	1,215,441	1,168,261
Fair Value	1,215,441	1,168,261
Cash and Cash Equivalents	1,215,441	1,168,261
US Treasury and Agencies \| Fair Value Level 1
Financial Instruments [Line Items]
Cost	324,199	212,436
Unrealized Gain	398	178
Unrealized (Loss)	(42)	(27)
Fair Value	324,555	212,587
Short-Term Investments	299,335	204,549
Restricted Cash & Investments	25,220	8,038
Mutual Funds \| Fair Value Level 1
Financial Instruments [Line Items]
Cost	36,034	18,784
Unrealized Gain	4,430	2,974
Unrealized (Loss)	(5)
Fair Value	40,459	21,758
Other Assets	40,459	21,758
Government-Sponsored Enterprises \| Fair Value Level 2
Financial Instruments [Line Items]
Cost	77,613	27,666
Unrealized Gain	27	41
Unrealized (Loss)	(38)	(15)
Fair Value	77,602	27,692
Short-Term Investments	77,602	27,692
Foreign Government Bonds \| Fair Value Level 2
Financial Instruments [Line Items]
Cost	56,892	35,438
Unrealized Gain	72	57
Unrealized (Loss)	(39)	(28)
Fair Value	56,925	35,467
Short-Term Investments	56,925	35,467
Mortgage Backed Securities - Residential \| Fair Value Level 2
Financial Instruments [Line Items]
Cost	28,538	27,067
Unrealized Gain	93	59
Unrealized (Loss)	(144)	(182)
Fair Value	28,487	26,944
Short-Term Investments	28,487	26,944
Mortgage Backed Securities - Commercial \| Fair Value Level 2
Financial Instruments [Line Items]
Cost	141,885	112,642
Unrealized Gain	39	100
Unrealized (Loss)	(720)	(809)
Fair Value	141,204	111,933
Short-Term Investments	$ 141,204	$ 111,933

Name:	lrcx_FinancialInstrumentsLineItems
Namespace Prefix:	lrcx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This item represents the cost of debt and equity securities, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any.

+ References

No definition available.

+ Details

Name:	lrcx_InvestmentsAmortizedCost
Namespace Prefix:	lrcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the unrealized gain on debt or equity securities.

+ References

No definition available.

+ Details

Name:	lrcx_InvestmentsUnrealizedGain
Namespace Prefix:	lrcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the unrealized loss on debt or equity securities.

+ References

No definition available.

+ Details

Name:	lrcx_InvestmentsUnrealizedLoss
Namespace Prefix:	lrcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fair value of cash and investments that is restricted as to withdrawal or usage, valued by the entity on a recurring basis. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits classified as long-term; that is not expected to be released from such existing restrictions within one year of the balance sheet date or operating cycle, whichever is longer. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet.

+ References

No definition available.

+ Details

Name:	lrcx_RestrictedCashFairValueDisclosure
Namespace Prefix:	lrcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents investments classified as available for sale reported on the balance sheet at period end measured at fair value on a recurring basis by the entity.

+ References

No definition available.

+ Details

Name:	lrcx_ShortTermInvestmentsFairValueDisclosure
Namespace Prefix:	lrcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

+ Details

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

+ Details

Name:	us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of other assets.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherAssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FairValueByAssetClassAxis=lrcx_MutualFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_BankTimeDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_CashMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: