Note 5 - Property and Equipment, Net (Details Textual) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Depreciation, Including Amortization of Leasehold Improvements	$ 0.2	$ 0.2	$ 0.3	$ 0.4

Depreciation cost, including the amortization of leasehold improvements.

No definition available.

Name:	zvia_DepreciationIncludingAmortizationOfLeaseholdImprovements
Namespace Prefix:	zvia_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration