Investments (Summary of Short-term Investments by Type) (Details) - USD ($) $ in Thousands	Sep. 23, 2018	Jun. 24, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 331,637	$ 270,235
Gross Unrealized Gains	37	53
Gross Unrealized Losses	(2,451)	(2,127)
Estimated Fair Value	329,223	268,161
Debt Securities, Available-for-sale, Current	329,223	268,161
Variable Rate Demand Obligation [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	400	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	400	0
Debt Securities, Available-for-sale, Current	400
Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	104,136	110,198
Gross Unrealized Gains	2	17
Gross Unrealized Losses	(1,222)	(939)
Estimated Fair Value	102,916	109,276
Debt Securities, Available-for-sale, Current	102,916
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	146,526	77,871
Gross Unrealized Gains	35	36
Gross Unrealized Losses	(1,159)	(1,150)
Estimated Fair Value	145,402	76,757
Debt Securities, Available-for-sale, Current	145,402
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,667	3,922
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(10)	(38)
Estimated Fair Value	4,657	3,884
Debt Securities, Available-for-sale, Current	4,657
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	44,294	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(60)	0
Estimated Fair Value	44,234	0
Debt Securities, Available-for-sale, Current	44,234
Commercial Paper [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,978	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	1,978	0
Debt Securities, Available-for-sale, Current	1,978
Non-US [Member] \| Certificates of Deposit [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,136	77,744
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	29,136	77,744
Debt Securities, Available-for-sale, Current	29,136
UNITED STATES \| Certificates of Deposit [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	500	500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	500	$ 500
Debt Securities, Available-for-sale, Current	$ 500

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

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

- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

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

- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

No definition available.

+ Details

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

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

No definition available.

+ Details

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

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26626-111562

+ Details

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

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_VariableRateDemandObligationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	invest_InvestmentGeographicRegionAxis=us-gaap_NonUsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	invest_InvestmentGeographicRegionAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: