Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

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

- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(ii)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount included in accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan expected to be recognized in net periodic benefit (cost) credit for fiscal year following most recent annual statement of financial position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (s)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

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

- Definition

Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

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

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum amount the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum maturity period for fixed income plan assets invested in indexed-linked gilts.

+ References

No definition available.

+ Details

Name:	viav_DefinedBenefitPlanFixedIncomeAssetsMaturityPeriodMinimum
Namespace Prefix:	viav_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the first level of employee's contributions expressed as a percentage of compensation which is matched by the employer.

+ References

No definition available.

+ Details

Name:	viav_DefinedContributionPlanEmployerMatchEmployeeContributionLevelOne
Namespace Prefix:	viav_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the second level of employee' contributions expressed as a percentage of compensation which is matched by the employer.

+ References

No definition available.

+ Details

Name:	viav_DefinedContributionPlanEmployerMatchEmployeeContributionLevelTwo
Namespace Prefix:	viav_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the employer matching contribution of the first level of employee's contributions.

+ References

No definition available.

+ Details

Name:	viav_DefinedContributionPlanEmployerMatchLevelOne
Namespace Prefix:	viav_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the employer matching contribution of the second level of employee's contributions.

+ References

No definition available.

+ Details

Name:	viav_DefinedContributionPlanEmployerMatchLevelTwo
Namespace Prefix:	viav_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	viav_DefinedContributionPlansDisclosureAbstract
Namespace Prefix:	viav_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=us-gaap_ForeignPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Pension and Other Benefit Plans - Additional Information (Details) £ in Millions	12 Months Ended
	Jun. 29, 2019 USD ($)	Jun. 29, 2019 GBP (£)	Jun. 30, 2018 USD ($)	Jun. 30, 2018 GBP (£)	Jul. 01, 2017 USD ($)
Employee 401(k) Plans
Maximum contribution by an employee, as percentage of annual compensation	50.00%	50.00%
Maximum amount of contribution by an employee in a calendar year	$ 19,000
Employer match of employee's contributions of the first 3% of eligible compensation (as a percent)	100.00%	100.00%
Percentage of eligible compensation, matched 100% by employer	3.00%	3.00%
Employer match of employee's contributions of the next 2% of eligible compensation (as a percent)	50.00%	50.00%
Percentage of eligible compensation, matched 50% by employer	2.00%	2.00%
Company's matching contribution to the plan	$ 4,900,000		$ 4,200,000		$ 4,100,000
Employee Defined Benefit Plans
Required contributions expected in next fiscal year	$ 0
Minimum maturity period for investment in index-linked Gilts	5 years	5 years
Other Post Retirement Benefit Plans
Employee Defined Benefit Plans
Benefit obligation	$ 400,000		400,000
Pension Benefit Plans
Employee Defined Benefit Plans
Future amortization of losses	2,900,000
Benefit obligation	140,000,000.0		136,700,000		$ 133,400,000
Employer contributions	5,100,000		6,100,000
United Kingdom \| Pension Benefit Plans
Employee Defined Benefit Plans
Employer contributions	$ 600,000	£ 0.5	$ 1,000,000.0	£ 0.8