Annual report pursuant to Section 13 and 15(d)

Stockholders' equity - Restricted Stock Activity (Details)

v3.6.0.2
Stockholders' equity - Restricted Stock Activity (Details) - Restricted stock
12 Months Ended
Dec. 31, 2016
$ / shares
shares
Tecogen  
Unvested Restricted Stock [Roll Forward]  
Unvested, Beginning (shares) | shares 163,350
Granted (shares) | shares 0
Vested (shares) | shares (85,842)
Forfeited (shares) | shares 0
Unvested, Ending (shares) | shares 77,508
Weighted Average Grant Date Fair Value [Roll Forward]  
Unvested, Beginning (usd per share) | $ / shares $ 1.31
Granted (usd per share) | $ / shares 0.00
Vested (usd per share) | $ / shares 1.31
Forfeited (usd per share) | $ / shares 0.00
Unvested, Ending (usd per share) | $ / shares $ 1.31
Ilois  
Unvested Restricted Stock [Roll Forward]  
Unvested, Beginning (shares) | shares 160,000
Granted (shares) | shares 0
Vested (shares) | shares (160,000)
Forfeited (shares) | shares 0
Unvested, Ending (shares) | shares 0
Weighted Average Grant Date Fair Value [Roll Forward]  
Unvested, Beginning (usd per share) | $ / shares $ 0.10
Granted (usd per share) | $ / shares 0.00
Vested (usd per share) | $ / shares 0.10
Forfeited (usd per share) | $ / shares 0.00
Unvested, Ending (usd per share) | $ / shares $ 0.00