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6. Customer Concentrations (Details Narrative)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Customer Concentrations Details Narrative
Major customer, % of sales	62.00%	46.00%	66.00%	51.00%

X

- Definition

Percentage of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_EntityWideRevenueMajorCustomerPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ZMTP_CustomerConcentrationsDetailsNarrativeAbstract
Namespace Prefix:	ZMTP_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration