Summary of significant accounting policies - Additional Information (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Jul. 22, 2013 |
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| Debt Instrument [Line Items] | |||
| Allowance for doubtful accounts | $ 29,665 | $ 50,000 | |
| Bill and Hold Transactions | 2,588,458 | 928,900 | |
| Advertising expense | 134,000 | 184,000 | |
| Research and development | 667,064 | 591,585 | |
| Revolving credit facility | |||
| Debt Instrument [Line Items] | |||
| Letter of credit outstanding | $ 294,802 | ||
| Revolving credit facility | Chief Executive Officer (John N. Hatsopoulos) | |||
| Debt Instrument [Line Items] | |||
| Bank credit facility | $ 1,055,000 | ||
| Demand notes | Chief Executive Officer (John N. Hatsopoulos) | |||
| Debt Instrument [Line Items] | |||
| Demand notes payable, related party, current | 2,000,000 | ||
| Demand notes payable, withdrawal limit per quarter | $ 250,000 | ||
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- Definition Line Of Credit Facility, Maximum Withdrawal Limit Per Financial Calendar Quarter No definition available.
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- Definition Research And Development Expense, Gross No definition available.
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- Definition Revenue Recognized, Bill And Hold Transactions No definition available.
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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 A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. No definition available.
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount for notes payable (written promise to pay), due to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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