Income Taxes - Income (Loss) Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 27, 2020	Jun. 29, 2019	Jun. 30, 2018
Income (loss) before income taxes
Domestic	$ (35.1)	$ (66.9)	$ (112.5)
Foreign	129.2	106.2	76.8
Income (loss) before income taxes	$ 94.1	$ 39.3	$ (35.7)

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