Balance Sheet and Other Details - Accounts Receivable Reserves and Allowances (Details) $ in Millions	3 Months Ended
Sep. 30, 2017 USD ($)
Allowance for doubtful accounts
Components of accounts receivable reserves and allowances
Beginning balance	$ 1.6
Acquisition of Trilithic	0.1
Charged to Costs and Expenses	0.0
Adjustments	0.0
Ending balance	1.7
Sales allowance
Components of accounts receivable reserves and allowances
Beginning balance	3.4
Ending balance	2.0
Total accounts receivable reserves and allowances
Components of accounts receivable reserves and allowances
Beginning balance	5.0
Ending balance	$ 3.7

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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

- Definition

Amount of increase (decrease) in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from adjustments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

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

- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

+ Details

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

- Definition

Amount of increase in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from charges to costs and expenses.

+ References

+ Details

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

- Definition

+ References

+ Details

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

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForDoubtfulAccountsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForSalesReturnsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=viav_AllowanceForDoubtfulAccountAndSalesReturnsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: