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)

v3.7.0.1

Stock-based compensation - Stock Option Activity (Details) - Tecogen - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Stock Options Outstanding [Roll Forward]
Beginning (shares)	1,117,918
Granted (shares)	3,000
Exercised (shares)	(61,140)
Canceled and forfeited (shares)	0
Expired (shares)	0
Ending (shares)	1,059,778	1,117,918
Exercisable (shares)	783,153
Vested and expected to vest (shares)	1,018,284
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Granted (dollars per share)	$ 3.72
Exercise Price Per Share, Outstanding, Maximum (dollars per share)		$ 5.39
Weighted Average Exercise Price [Roll Forward]
Beginning (usd per share)	3.10
Granted (usd per share)	3.72
Exercised (usd per share)	1.75
Canceled and forfeited (usd per share)	0.00
Expired (usd per share)	0.00
Ending (usd per share)	3.18	$ 3.10
Exercisable (usd per share)	2.73
Vested and expected to vest (usd per share)	$ 3.13
Weighted Average Remaining Life	5 years 1 month 12 days	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, Aggregate Intrinsic Value	$ 1,000,757	$ 1,415,150
Exercisable, Aggregate Intrinsic Value	993,591
Vested and expected to vest, Aggregate Intrinsic Value	$ 999,682
Minimum
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Outstanding, Minimum (per share)	$ 0.79	$ 0.79
Exercise Price Per Share, Exercised (dollars per share)	0.79
Maximum
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Exercised (dollars per share)	2.00
Exercise Price Per Share, Outstanding, Maximum (dollars per share)	$ 5.39

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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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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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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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