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Commitments and contingencies - Agreement with Digital Energy Corp. (Details) (USD $)
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Mar. 31, 2015
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| Revolving Credit Facility [Member] | |
| Guarantor Obligations [Line Items] | |
| Letter of credit outstanding |
$ 583,073us-gaap_LettersOfCreditOutstandingAmount / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember |
| Chief Executive Officer (John N. Hatsopoulos) | Letter of Credit [Member] | |
| Guarantor Obligations [Line Items] | |
| Collateralized Financings |
$ 1,055,000us-gaap_CollateralizedFinancings / us-gaap_CreditFacilityAxis = us-gaap_LetterOfCreditMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = us-gaap_ChiefExecutiveOfficerMember |
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- Definition
The value of the collateral (typically cash) that the entity receives in a financing transaction in exchange for securities lent. This item represents a liability in the financial statements of the lender of the securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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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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- Details
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- Details
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