Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Stock Option Activity (Details)

v3.20.2
Stock-Based Compensation - Stock Option Activity (Details) - Tecogen - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2020
Dec. 31, 2019
Stock Options Outstanding [Roll Forward]    
Beginning (shares) 1,352,874  
Granted (shares) 0  
Exercised (shares) (1,000)  
Canceled and forfeited (shares) (87,278)  
Ending (shares) 1,264,596 1,352,874
Exercisable (shares) 976,929  
Vested and expected to vest (shares) 1,221,446  
Exercise Price Per Share [Abstract]    
Exercise Price Per Share, Outstanding, Minimum (per share) $ 0.79 $ 0.79
Exercise Price Per Share, Outstanding, Maximum (dollars per share) 10.33 10.33
Exercise Price Per Share, Exercised (dollars per share) 1.20  
Weighted Average Exercise Price [Roll Forward]    
Beginning (usd per share) 3.57  
Granted (usd per share)  
Exercised (usd per share) 1.20  
Canceled and forfeited (usd per share) 1.80  
Ending (usd per share) 3.69 $ 3.57
Exercisable (usd per share) 3.71  
Vested and expected to vest (usd per share) $ 3.70  
Weighted Average Remaining Life 4 years 12 months 7 days 5 years 3 months 20 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]    
Outstanding, Aggregate Intrinsic Value $ 0 $ 95,381
Exercisable, Aggregate Intrinsic Value 0  
Vested and expected to vest, Aggregate Intrinsic Value $ 0  
Minimum    
Exercise Price Per Share [Abstract]    
Exercise Price, Canceled and Forfeited (dollars per share) $ 1.20  
Maximum    
Exercise Price Per Share [Abstract]    
Exercise Price, Canceled and Forfeited (dollars per share) $ 4.50