Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies - Concentration of Credit Risk (Details)

v2.4.1.9
Summary of significant accounting policies - Concentration of Credit Risk (Details) (USD $)
12 Months Ended
Dec. 31, 2014
customer
Dec. 31, 2013
customer
Concentration Risk [Line Items]    
Cash, FDIC Insured Amount 250,000us-gaap_CashFDICInsuredAmount  
Cash, Uninsured Amount 1,272,500us-gaap_CashUninsuredAmount 7,410,000us-gaap_CashUninsuredAmount
Customer concentration risk | Revenues    
Concentration Risk [Line Items]    
Number of customer representing more than 10% of revenues or trade accounts receivable 353tcgn_ConcentrationRiskNumberOfSignificantCustomers
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
0tcgn_ConcentrationRiskNumberOfSignificantCustomers
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
Concentration risk, percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
 
Customer concentration risk | Trade accounts receivable    
Concentration Risk [Line Items]    
Number of customer representing more than 10% of revenues or trade accounts receivable 1tcgn_ConcentrationRiskNumberOfSignificantCustomers
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_AccountsReceivableMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
1tcgn_ConcentrationRiskNumberOfSignificantCustomers
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_AccountsReceivableMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
Concentration risk, percentage 13.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_AccountsReceivableMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
22.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_AccountsReceivableMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember