Fair Value Measurements (Details) (Fair Value, Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Liabilities:
Contingent consideration	$ 7
Fair Value, Inputs, Level 3
Liabilities:
Contingent consideration	$ 7

Fair value, as of the acquisition date, of potential payments under the contingent consideration arrangement including cash and shares.

No definition available.

Name:	zyxi_BusinessAcquisitionContingentConsiderationAtFairValueOne
Namespace Prefix:	zyxi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant