Quarterly report pursuant to Section 13 or 15(d)

Cover
- Document and Entity Information Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Description of business and summary of significant accounting policies (Policies)
Notes Tables
Notes Details

Stock-based compensation - Stock Option Activity (Details)

v3.3.0.814

Stock-based compensation - Stock Option Activity (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Expired (per share)		$ 0.00
Tecogen
Stock Options Outstanding [Roll Forward]
Beginning (shares)		1,356,325
Granted (shares)		160,000
Exercised (shares)		(222,375)
Canceled and forfeited (shares)		(28,750)
Expired (shares)		0
Ending (shares)		1,265,200
Exercisable (shares)		776,619
Vested and expected to vest (shares)		1,165,200
Weighted Average Exercise Price [Roll Forward]
Beginning (usd per share)		$ 2.77
Granted (usd per share)		3.43
Exercised (usd per share)		1.62
Canceled and forfeited (usd per share)		2.45
Expried (usd per share)		0.00
Ending (usd per share)		3.06
Exercisable (usd per share)		2.30
Vested and expected to vest (usd per share)		$ 2.90
Weighted Average Remaining Life		6 years 3 months	5 years 1 month 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, Aggregate Intrinsic Value		$ 955,919			$ 3,618,935
Exercisable, Aggregate Intrinsic Value		935,747
Vested and expected to vest, Aggregate Intrinsic Value		$ 955,919
Minimum \| Tecogen
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Outstanding (per share)	$ 1.2			$ 1.20
Exercise Price Per Share, Granted (per share)		$ 1.20
Exercise Price Per Share, Cancelled and forfeited (per share)				1.2
Maximum \| Tecogen
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Outstanding (per share)	$ 5.39			5.39
Exercise Price Per Share, Granted (per share)		$ 2.60
Exercise Price Per Share, Cancelled and forfeited (per share)				$ 4.50

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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