Quarterly report pursuant to Section 13 or 15(d)

Stock-based compensation - Stock Option Activity (Details)

v2.4.0.8
Stock-based compensation - Stock Option Activity (Details) (USD $)
3 Months Ended 12 Months Ended 3 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2014
Mar. 31, 2014
Tecogen
Dec. 31, 2012
Tecogen
Dec. 31, 2013
Tecogen
Mar. 31, 2014
Ilois
Mar. 31, 2013
Ilois
Dec. 31, 2013
Ilois
Mar. 31, 2014
Minimum
Tecogen
Dec. 31, 2012
Minimum
Tecogen
Mar. 31, 2014
Minimum
Ilois
Dec. 31, 2012
Minimum
Ilois
Mar. 31, 2014
Maximum
Tecogen
Dec. 31, 2012
Maximum
Tecogen
Mar. 31, 2014
Maximum
Ilois
Dec. 31, 2012
Maximum
Ilois
Stock Options Outstanding [Roll Forward]                              
Beginning (shares)   1,148,000     575,000                    
Granted (shares)   43,325     0                    
Exercised (shares)   (5,000)     0                    
Canceled and forfeited (shares)   0     0                    
Expired (shares)   0     0                    
Ending (shares)   1,186,325     575,000                    
Exercisable (shares)   919,250     125,000                    
Vested and expected to vest (shares)   1,186,325     575,000                    
Exercise Price Per Share [Abstract]                              
Exercise Price Per Share, Beginning (per share)               $ 1.2 $ 1.20 $ 0.10 $ 0.10 $ 4.5 $ 4.50 $ 0.50 $ 0.50
Exercise Price Per Share, Granted (per share)   $ 4.5     $ 0.00                    
Exercise Price Per Share, Exercised (per share)   $ 1     $ 0                    
Exercise Price Per Share, Cancelled and forfeited (per share)   $ 0     $ 0                    
Exercise Price Per Share, Expired (per share) $ 0       $ 0                    
Exercise Price Per Share, Ending (per share)               $ 1.2 $ 1.20 $ 0.10 $ 0.10 $ 4.5 $ 4.50 $ 0.50 $ 0.50
Weighted Average Exercise Price [Roll Forward]                              
Beginning (usd per share)   $ 2.13     $ 0.29                    
Granted (usd per share)   $ 4.50     $ 0.00                    
Exercised (usd per share)   $ 1     $ 0                    
Canceled and forfeited (usd per share)   $ 0.00     $ 0                    
Expried (usd per share)   $ 0.00     $ 0                    
Ending (usd per share)   $ 2.22     $ 0.29                    
Exercisable (usd per share)   $ 1.90     $ 0.50                    
Vested and expected to vest (usd per share)   $ 2.22     $ 0.29                    
Weighted Average Remaining Life   5 years 8 months 23 days 5 years 9 months 18 days   6 years 2 months 9 days 6 years 5 months 9 days                  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]                              
Outstanding, Aggregate Intrinsic Value   $ 2,704,600   $ 2,721,100 $ 120,000   $ 120,000                
Exercisable, Aggregate Intrinsic Value   2,387,075     0                    
Vested and expected to vest, Aggregate Intrinsic Value   $ 2,704,600     $ 120,000