Income Taxes - Income (Loss) Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 29, 2019	Jun. 30, 2018	Jul. 01, 2017
Income (loss) before income taxes
Domestic	$ (66.9)	$ (112.5)	$ 90.5
Foreign	106.2	76.8	89.5
(Loss) income before income taxes	$ 39.3	$ (35.7)	$ 180.0

Sum of operating profit and nonoperating income or expense from continuing operations before income or loss from income taxes.

No definition available.

Name:	viav_IncomeLossFromContinuingOperationsBeforeIncomeTaxDomesticAndForeign
Namespace Prefix:	viav_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration