General form of registration statement for all companies including face-amount certificate companies

Commitments and contingencies - Agreement with Digital Energy Corp. (Details)

v2.4.0.8
Commitments and contingencies - Agreement with Digital Energy Corp. (Details) (USD $)
Oct. 26, 2011
Financial guarantee
Mar. 31, 2014
Revolving credit facility
Dec. 31, 2013
Revolving credit facility
Mar. 31, 2014
Chief Executive Officer (John N. Hatsopoulos)
Letter of credit
Dec. 31, 2013
Chief Executive Officer (John N. Hatsopoulos)
Letter of credit
Guarantor Obligations [Line Items]          
Letter of credit outstanding $ 180,000 $ 583,073 $ 583,073    
Certificate of deposit securing letter of credit 180,000        
Promissory note receivable amount 180,000        
Promissory note receivable, stated interest rate 6.00%        
Collateralized financings       $ 1,055,000 $ 1,055,000