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

Stock-based compensation - Stock Option Activity (Details)

v2.4.0.8
Stock-based compensation - Stock Option Activity (Details) (USD $)
 6 Months Ended 12 Months Ended
Jun. 30, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Stock Options Outstanding [Roll Forward]          
Beginning (in shares) 1,096,500        
Granted (in shares) 37,500        
Exercised (in shares) 0        
Canceled and forfeited (in shares) 0        
Expired (in shares) 0        
Ending (in shares) 1,134,000 1,096,500      
Exercisable (in shares) 812,313        
Vested and expected to vest (in shares) 1,134,000        
Weighted Average Exercise Price [Roll Forward]          
Beginning (in dollars per share) $ 1.96        
Granted (in dollars per share) $ 3.20        
Exercised (in dollars per share) $ 0        
Canceled and forfeited (in dollars per share) $ 0        
Expired (in dollars per share) $ 0        
Ending (in dollars per share) $ 2.00 $ 1.96      
Exercisable (in dollars per share) $ 1.72        
Vested and expected to vest (in dollars per share) $ 2.00        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]          
Outstanding, Weighted Average Remaining Life 4 years 2 months 8 days 4 years 7 months 28 days      
Outstanding, Aggregate Intrinsic Value $ 1,356,400 $ 1,356,400      
Exercisable, Aggregate Intrinsic Value 1,201,075        
Vested and expected to vest, Aggregate Intrinsic Value 1,356,400        
Exercise Price Per Share [Abstract]          
Outstanding, Exercise Price Lower Range Limit (in dollars per share)   $ 0.12      
Granted, Exercise Price (in dollars per share) $ 0        
Exercised, Exercise Price (in dollars per share) $ 0        
Maximum [Member]
          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]          
Outstanding, Weighted Average Remaining Life   7 years 5 months 8 days      
Exercise Price Per Share [Abstract]          
Outstanding, Exercise Price Lower Range Limit (in dollars per share) $ 3.20 $ 3.20      
Minimum [Member]
          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]          
Outstanding, Weighted Average Remaining Life 7 years 2 months 8 days        
Exercise Price Per Share [Abstract]          
Outstanding, Exercise Price Lower Range Limit (in dollars per share) $ 0.12 $ 0.12      
Tecogen
          
Stock Options Outstanding [Roll Forward]          
Beginning (in shares) 1,096,500 1,095,250 620,000 595,000  
Granted (in shares)   17,500 511,500 25,000  
Exercised (in shares)   0 0    
Canceled and forfeited (in shares)   (15,938) 0    
Repurchased (in shares)     (12,500)    
Expired (in shares)   (313) (23,750)    
Ending (in shares)   1,096,500 1,095,250 620,000 595,000
Exercisable (in shares)   662,563 418,438 307,500  
Vested and expected to vest (in shares)   1,096,500 1,025,250 620,000  
Weighted Average Exercise Price [Roll Forward]          
Beginning (in dollars per share) $ 1.96 $ 1.92 $ 1.28 $ 1.28  
Granted (in dollars per share)   $ 3.20 $ 2.60 $ 2.60  
Exercised (in dollars per share)   $ 0 $ 0    
Canceled and forfeited (in dollars per share)   $ 1.28 $ 0    
Repurchased (in dollars per share)     $ 1.00    
Expired (in dollars per share)   $ 2.60 $ 1.48    
Ending (in dollars per share)   $ 1.96 $ 1.92 $ 1.28 $ 1.28
Exercisable (in dollars per share)   $ 1.56 $ 1.24 $ 1.12  
Vested and expected to vest (in dollars per share)   $ 1.96 $ 1.92 $ 1.20  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]          
Outstanding, Weighted Average Remaining Life   4 years 7 months 28 days 5 years 6 months 11 days 3 years 3 months 18 days 4 years 3 months 7 days
Outstanding, Aggregate Intrinsic Value   1,356,400 1,387,150 793,500 793,500
Exercisable, Aggregate Intrinsic Value   1,096,225 815,125 451,000  
Vested and expected to vest, Aggregate Intrinsic Value   1,356,400 1,387,150 793,500  
Exercise Price Per Share [Abstract]          
Outstanding, Exercise Price Lower Range Limit (in dollars per share)   $ 0.12 $ 0.12 $ 0.12 $ 0.12
Outstanding, Exercise Price Upper Range Limit (in dollars per share)   $ 3.20 $ 2.80 $ 2.60 $ 2
Granted, Exercise Price (in dollars per share) $ 3.20 $ 3.20   $ 2.60  
Granted, Exercise Price Lower Range Limit (in dollars per share)     $ 2.60    
Granted, Exercise Price Upper Range Limit (in dollars per share)     $ 2.80    
Exercised, Exercise Price (in dollars per share) $ 0 $ 0 $ 0    
Canceled and Forfeited, Exercise Price (in dollars per share)     $ 0    
Canceled and Forfeited, Exercise Price Lower Range Limit (in dollars per share)   $ 1.20      
Canceled and Forfeited, Exercise Price Upper Range Limit (in dollars per share)   $ 2.60      
Repurchased, Exercise Price (in dollars per share)     $ 1.00    
Expired, Exercise Price (in dollars per share) $ 0 $ 2.60      
Expired, Exercise Price Per Share, Lower Range Limit (in dollars per share)     $ 1.20    
Expired, Exercise Price Per Share, Upper Range Limit (in dollars per share)     $ 2.60    
Ilois
          
Stock Options Outstanding [Roll Forward]          
Beginning (in shares) 575,000 525,000 300,000 300,000  
Granted (in shares) 0 50,000 225,000 0  
Exercised (in shares) 0 0 0 0  
Canceled and forfeited (in shares) 0 0 0 0  
Expired (in shares) 0 0 0 0  
Ending (in shares) 575,000 575,000 525,000 300,000 300,000
Exercisable (in shares) 56,250 0 0 0  
Vested and expected to vest (in shares) 575,000 575,000 525,000 300,000  
Weighted Average Exercise Price [Roll Forward]          
Beginning (in dollars per share) $ 0.29 $ 0.27 $ 0.10 $ 0.10  
Granted (in dollars per share) $ 0 $ 0.50 $ 0.50 $ 0  
Exercised (in dollars per share) $ 0 $ 0 $ 0 $ 0  
Canceled and forfeited (in dollars per share) $ 0 $ 0 $ 0 $ 0  
Expired (in dollars per share) $ 0 $ 0 $ 0 $ 0  
Ending (in dollars per share) $ 0.29 $ 0.29 $ 0.27 $ 0.10 $ 0.10
Exercisable (in dollars per share) $ 0.50 $ 0.50 $ 0 $ 0  
Vested and expected to vest (in dollars per share) $ 0.29 $ 0.29 $ 0.27 $ 0.10  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]          
Outstanding, Weighted Average Remaining Life   7 years 5 months 8 days 8 years 2 months 23 days 8 years 4 months 2 days 9 years 4 months 2 days
Outstanding, Aggregate Intrinsic Value 120,000 120,000 120,000 120,000 120,000
Exercisable, Aggregate Intrinsic Value 0 0 0 0  
Vested and expected to vest, Aggregate Intrinsic Value $ 120,000 $ 120,000 $ 120,000 $ 120,000  
Exercise Price Per Share [Abstract]          
Outstanding, Exercise Price (in dollars per share)     $ 0.10 $ 0.10 $ 0.10
Outstanding, Exercise Price Lower Range Limit (in dollars per share) $ 0.10 $ 0.10 $ 0.10    
Outstanding, Exercise Price Upper Range Limit (in dollars per share) $ 0.50 $ 0.50 $ 0.50    
Granted, Exercise Price (in dollars per share)   $ 0.50 $ 0.50 $ 0  
Exercised, Exercise Price (in dollars per share)   $ 0 $ 0 $ 0  
Canceled and Forfeited, Exercise Price (in dollars per share) $ 0 $ 0 $ 0 $ 0  
Expired, Exercise Price (in dollars per share)   $ 0 $ 0 $ 0