Condensed Statement of Operations and Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net sales	$ 3,059,448us-gaap_SalesRevenueGoodsNet	$ 3,146,345us-gaap_SalesRevenueGoodsNet	$ 11,901,339us-gaap_SalesRevenueGoodsNet	$ 11,241,164us-gaap_SalesRevenueGoodsNet
Cost of goods sold	2,102,582us-gaap_CostOfGoodsSold	2,213,878us-gaap_CostOfGoodsSold	8,409,665us-gaap_CostOfGoodsSold	8,139,084us-gaap_CostOfGoodsSold
Gross profit	956,866us-gaap_GrossProfit	932,467us-gaap_GrossProfit	3,491,674us-gaap_GrossProfit	3,102,080us-gaap_GrossProfit
Operating expenses:
Selling	408,601us-gaap_SellingExpense	352,780us-gaap_SellingExpense	1,446,110us-gaap_SellingExpense	1,572,632us-gaap_SellingExpense
General and administrative	249,455us-gaap_GeneralAndAdministrativeExpense	292,552us-gaap_GeneralAndAdministrativeExpense	1,052,326us-gaap_GeneralAndAdministrativeExpense	1,316,402us-gaap_GeneralAndAdministrativeExpense
Research and development	271,162us-gaap_ResearchAndDevelopmentExpense	308,667us-gaap_ResearchAndDevelopmentExpense	1,132,791us-gaap_ResearchAndDevelopmentExpense	919,722us-gaap_ResearchAndDevelopmentExpense
Total	929,218us-gaap_OperatingExpenses	953,999us-gaap_OperatingExpenses	3,631,227us-gaap_OperatingExpenses	3,808,756us-gaap_OperatingExpenses
Operating profit (loss)	27,648us-gaap_OperatingIncomeLoss	(21,532)us-gaap_OperatingIncomeLoss	(139,553)us-gaap_OperatingIncomeLoss	(706,676)us-gaap_OperatingIncomeLoss
Other income (expense):
Interest income	6us-gaap_InvestmentIncomeInterest	7us-gaap_InvestmentIncomeInterest	33us-gaap_InvestmentIncomeInterest	39us-gaap_InvestmentIncomeInterest
Other, net	(23,084)us-gaap_OtherNonoperatingIncomeExpense	(14,200)us-gaap_OtherNonoperatingIncomeExpense	269,086us-gaap_OtherNonoperatingIncomeExpense	(354,403)us-gaap_OtherNonoperatingIncomeExpense
Total other income (expense), net	(23,078)us-gaap_NonoperatingIncomeExpense	(14,193)us-gaap_NonoperatingIncomeExpense	269,119us-gaap_NonoperatingIncomeExpense	(354,364)us-gaap_NonoperatingIncomeExpense
Income (loss) before income taxes	4,570	(35,725)	129,566	(1,061,040)
Income taxes (benefit)	0us-gaap_IncomeTaxExpenseBenefit	1,331us-gaap_IncomeTaxExpenseBenefit	7,080us-gaap_IncomeTaxExpenseBenefit	3,944us-gaap_IncomeTaxExpenseBenefit
Net income (loss)	4,570us-gaap_NetIncomeLoss	(37,056)us-gaap_NetIncomeLoss	122,486us-gaap_NetIncomeLoss	(1,064,984)us-gaap_NetIncomeLoss
Other comprehensive income (loss):
Foreign currency translation adjustments	0	362	(3,621)	(7,504)
Foreign currency translation recognition upon reclassification from accumulated other comprehensive income			(360,734)	0
Unrealized gain (loss) for the period			0ZMTP_UnrealizedGainLossForPeriod	272,909ZMTP_UnrealizedGainLossForPeriod
Net comprehensive income (loss)	$ 4,570	$ (36,694)	$ (241,869)	$ (799,579)
Net income (loss) per share: Basic and Diluted	$ 0us-gaap_EarningsPerShareBasicAndDiluted	$ 0.00us-gaap_EarningsPerShareBasicAndDiluted	$ 0.02us-gaap_EarningsPerShareBasicAndDiluted	$ (0.14)us-gaap_EarningsPerShareBasicAndDiluted
Weighted average common and common equivalent shares:
Basic	7,985,204	7,982,704	7,982,704	7,363,482
Diluted	7,999,371	7,982,704	7,982,704	7,363,482
Basic and diluted	0	0	7,982,704	7,363,482

Total costs related to goods produced and sold during the reporting period.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 2

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2(a))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688