Long Term Debt and Other Borrowings - Components of Convertible Notes (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Jun. 25, 2017 USD ($) $ / shares shares	Jun. 26, 2016 USD ($)
2018 Notes
Debt Instrument [Line Items]
Remaining amortization period (years)	9 months 23 days	1 year 10 months 24 days
Fair value of notes (Level 2)	$ 1,125,561
Conversion rate (shares of common stock per $1 of principal amount of notes)	0.0165702
Conversion price (per share of common stock) \| $ / shares	$ 60.35
If-converted value in excess of par value	$ 677,876
Estimated share dilution using average quarterly stock price of $80.08 per share (shares) \| shares	4,334
Average quarterly stock price (usd per share) \| $ / shares	$ 145.28
2018 Notes \| Permanent Equity
Debt Instrument [Line Items]
Carrying amount of equity component, net of tax	$ 89,604	$ 72,992
2018 Notes \| Temporary Equity
Debt Instrument [Line Items]
Carrying amount of equity component, net of tax	$ 15,186	$ 31,894
2041 Notes
Debt Instrument [Line Items]
Remaining amortization period (years)	23 years 9 months 23 days	24 years 10 months 24 days
Fair value of notes (Level 2)	$ 2,809,857
Conversion rate (shares of common stock per $1 of principal amount of notes)	0.0297371
Conversion price (per share of common stock) \| $ / shares	$ 33.63
If-converted value in excess of par value	$ 2,217,277
Estimated share dilution using average quarterly stock price of $80.08 per share (shares) \| shares	14,423
Average quarterly stock price (usd per share) \| $ / shares	$ 145.28
2041 Notes \| Permanent Equity
Debt Instrument [Line Items]
Carrying amount of equity component, net of tax	$ 156,374	$ 152,397
2041 Notes \| Temporary Equity
Debt Instrument [Line Items]
Carrying amount of equity component, net of tax	$ 154,675	$ 175,658

Estimated Number of Diluted Shares Outstanding

No definition available.

Name:	lrcx_EstimatedNumberofDilutedSharesOutstanding
Namespace Prefix:	lrcx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Convertible Security
-URI http://asc.fasb.org/extlink&oid=6509036

+ Details

Name:	us-gaap_ConvertibleDebtFairValueDisclosures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031897-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Conversion Rate
-URI http://asc.fasb.org/extlink&oid=6509012

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleIfConvertedValueInExcessOfPrincipal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleRemainingDiscountAmortizationPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=lrcx_OnePointTwoFivePercentConvertibleSeniorNotesDueTwoThousandEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=lrcx_PermanentEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=lrcx_TemporaryEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=lrcx_TwoPointSixTwoFivePercentConvertibleSeniorNotesDueTwoThousandFortyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: