Balance Sheet and Other Details - Accounts Receivable Reserves and Allowances (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 29, 2019	Jun. 30, 2018	Jul. 01, 2017
Allowance for Doubtful Accounts Receivable
Balance at Beginning of Period	$ 2.4	$ 1.6	$ 2.2
Acquisitions	0.0	0.7	0.0
Charged to Costs and Expenses	1.4	(0.4)	(0.2)
Deduction	(1.8)	0.5	(0.4)
Balance at End of Period	$ 2.0	$ 2.4	$ 1.6

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.5)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130534-203044

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Balance Type:	debit
Period Type:	duration

- Definition

Allowance For Doubtful Accounts Receivable, Acquisitions

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Allowance For Doubtful Accounts Receivable, Currency Translation Adjustments And Write-Offs Against Allowance

+ References

No definition available.

+ Details

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Namespace Prefix:	viav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration