Capital Leases and Other Obligations (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015
Assembly equipment
Debt Instrument [Line Items]
Cost of assets under capital lease	461
Accumulated depreciation	129
Maximum
Debt Instrument [Line Items]
Imputed interest rate on lease	18.00%
Minimum
Debt Instrument [Line Items]
Imputed interest rate on lease	6.00%
Revised from September 1, 2014 through December 31, 2014
Debt Instrument [Line Items]
Lease Commencement Date	Jan. 01, 2015
Lease term	2 years
Fixed rental payments for each month	49
Revised from September 1, 2014 through December 31, 2014 \| Maximum
Debt Instrument [Line Items]
Lease termination date	Dec. 31, 2016

Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services.

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

- Definition

The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6455314&loc=d3e45014-112735

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

-Paragraph 40

-Subparagraph (Note 2)

-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

+ Details

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Data Type:	xbrli:monetaryItemType
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- Details

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Period Type:	duration

- Definition

Date which lease or group of leases is set to expire, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Term of the lessee's leasing arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Fixed rental payments for each month.

+ References

No definition available.

+ Details

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

- Definition

Imputed interest rate on capital lease.

+ References

No definition available.

+ Details

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Namespace Prefix:	zyxi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Lease commencement date.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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