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           Business and summary of significant accounting policies (Details) (USD $) 
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        12 Months Ended | |
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           Dec. 31, 2014 
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           Dec. 31, 2013 
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| Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
| Foreign currency transaction gains (losses) | $ (280,098)us-gaap_ForeignCurrencyTransactionGainLossRealized | $ 61,000us-gaap_ForeignCurrencyTransactionGainLossRealized | 
| Change in valuation allowance | (3,061,841)us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance | 10,249,612us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance | 
| Advertising expense | $ 1,700,000us-gaap_AdvertisingExpense | $ 1,500,000us-gaap_AdvertisingExpense | 
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- Definition 
          Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
          
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