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Subsequent events (Details) (USD $)
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0 Months Ended | 0 Months Ended | 12 Months Ended | 0 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Mar. 31, 2014
Chief Executive Officer (John N. Hatsopoulos)
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Mar. 26, 2014
Chief Executive Officer (John N. Hatsopoulos)
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Oct. 03, 2013
Demand notes
Chief Executive Officer (John N. Hatsopoulos)
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Nov. 30, 2012
Demand notes
Chief Executive Officer (John N. Hatsopoulos)
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Sep. 07, 2011
Demand notes
Chief Executive Officer (John N. Hatsopoulos)
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Sep. 10, 2008
Demand notes
Chief Executive Officer (John N. Hatsopoulos)
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Sep. 24, 2001
Convertible debentures
Chief Executive Officer (John N. Hatsopoulos)
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Sep. 24, 2001
Convertible debentures
Member of board of directors
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Oct. 18, 2013
Convertible debentures
Common stock
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Dec. 31, 2012
Convertible debentures
Common stock
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Oct. 18, 2013
Conversion of Accrued Interest Amount in 2012 [Member]
Convertible debentures
Member of board of directors
|
Sep. 30, 2012
Conversion of accrued interest
Convertible debentures
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Oct. 18, 2013
Conversion of accrued interest
Convertible debentures
Member of board of directors
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Sep. 24, 2011
Conversion of accrued interest
Convertible debentures
Member of board of directors
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May 11, 2009
Conversion of accrued interest
Convertible debentures
Member of board of directors
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| Subsequent Event [Line Items] | |||||||||||||||
| Principal amount | $ 450,000 | $ 300,000 | $ 750,000 | $ 250,000 | $ 100,000 | $ 200,000 | |||||||||
| Related party debt, stated interest rate | 6.00% | 6.00% | 6.00% | 5.00% | |||||||||||
| Debt conversion, amount converted | 90,967 | 6,100 | 72,960 | 90,967 | |||||||||||
| Debt conversion, number of shares issued | 75,806 | 85,242 | |||||||||||||
| Current portion of convertible debentures, related party | 6,913 | 4,367 | |||||||||||||
| Common stock issuable upon conversion | 555,556 | 2,161 | 970 | ||||||||||||
| Maximum borrowing capacity | $ 1,500,000 | $ 3,500,000 | |||||||||||||
| Conversion price in usd per share | $ 1.20 | $ 3.20 | $ 4.50 | ||||||||||||