Annual report pursuant to Section 13 and 15(d)

Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details Narrative)

Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details Narrative)								3 Months Ended	12 Months Ended
	Aug. 29, 2019 $ / shares shares	Jul. 25, 2019 $ / shares shares	Apr. 02, 2019 USD ($) $ / shares shares	Jan. 17, 2019 $ / shares shares	Jul. 26, 2018 $ / shares shares	May 01, 2018 USD ($) shares	Jan. 18, 2018 $ / shares shares	Dec. 31, 2019 USD ($) Integer $ / shares shares	Dec. 31, 2019 USD ($) Integer $ / shares shares	Dec. 31, 2018 USD ($) shares	Jan. 27, 2019 Integer shares	May 30, 2018 $ / shares	Jan. 27, 2018 Integer shares
Common stock exercise price per share \| $ / shares												$ 4.80
Option granted to purchase shares									129,500
Proceeds from exercise of stock options \| $									$ 133,000	$ 36,000
Unrecognized compensation cost related to unvested options \| $								$ 431,000	$ 431,000
Weighted average term for unrecognized and unvested option to be recognized									2 years 1 month 6 days
Stock option term, description									The term of the Ferguson Stock Option is seven (7) years from the grant date.
Number of options exercised									10,000
Allocated share-based compensation expense \| $									$ 179,000	$ 198,000
Number of common shares reserved for future issuance								681,300	681,300
Common Stock [Member]
Number of options exercised									32,400	10,000
Stock issued during period for services, shares									71,905	60,598
Robert Ferguson [Member]
Proceeds from exercise of stock options \| $						$ 36,500
Unrecognized compensation cost related to unvested options \| $								$ 123,000	$ 123,000
Stock option shall become exercisable upon attainment of performance milestone											30,000		10,000
Number of gallons \| Integer											2,000		3
Number of options exercised						10,000
Shares purchased from exercise of stock options						10,000
Loans payable \| $			$ 2,500,000
Warrant to purchase			60,000
Warrants exercise price \| $ / shares			$ 3.51
Warrant exercisable, description			The Warrant is exercisable six months from April 1, 2019 and expires on April 1, 2024 and remains outstanding at December 31, 2019.
Incentive Stock Options [Member]
Stock options granted vesting period				5 years
Option granted to purchase shares				105,000
Stock options, grants in period, exercise price \| $ / shares				$ 3.15
Stock options granted contractual term				6 years
Incentive Stock Options [Member] \| CEO [Member]
Option granted to purchase shares				25,000
Incentive Stock Options [Member] \| CFO [Member]
Option granted to purchase shares				15,000
Incentive Stock Options [Member] \| EVP [Member]
Option granted to purchase shares				15,000
January 27, 2021 [Member] \| Robert Ferguson [Member]
Stock option shall become exercisable upon attainment of performance milestone								60,000	60,000
Number of gallons \| Integer								50,000	50,000
2003 Outside Directors Stock Plan [Member]
Stock options granted vesting period									180 days
Stock options, expiration period									10 years
Share-based compensation arrangement by share-based payment award percentage of stock in lieu of fee payable									65.00%
Percentage of directors fees, description									The 2003 Plan also provides for the issuance to each outside director a number of shares of the Company's Common Stock in lieu of 65% or 100% (based on option elected by each director) of the fee payable to the eligible director for services rendered as a member of the Board of Directors ("Board"). The number of shares issued is determined at 75% of the market value as defined in the plan (the Company recognizes 100% of the market value of the shares issued).
Shares remaining available for issuance								262,312	262,312
2003 Outside Directors Stock Plan [Member] \| Common Stock [Member]
Number of shares available for issuance								1,100,000	1,100,000
2003 Outside Directors Stock Plan [Member] \| Re-election [Member]
Options granted to purchase shares								2,400	2,400
2003 Outside Directors Stock Plan [Member] \| Maximum [Member] \| Election [Member]
Options granted to purchase shares								6,000	6,000
2010 Stock Option Plan [Member]
Stock options, expiration period									10 years
Fair market value of shares, granted description									The term of each stock option granted was to be fixed by the Compensation and Stock Option Committee (the "Compensation Committee"), but no stock option was exercisable more than ten years after the grant date, or in the case of an incentive stock option granted to a 10% stockholder, five years after the grant date.
Percentage held by stockholder									10.00%
Shares remaining available for issuance								140,000	140,000
2010 Stock Option Plan [Member] \| Common Stock [Member]
Common stock exercise price per share \| $ / shares								$ 3.97	$ 3.97
Stock options, expiration date									May 15, 2022
Option granted to purchase shares									50,000
2010 Stock Option Plan [Member] \| Ten Percent of Stockholder [Member]
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term									5 years
2010 Stock Option Plan [Member] \| Officers and Employees [Member]
Number of shares available for issuance								200,000	200,000
2010 Stock Option Plan [Member] \| Maximum [Member] \| Officers and Employees [Member]
Options granted to purchase shares								200,000	200,000
2017 Stock Option Plan [Member]
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term									10 years
Fair market value of shares, granted description									The term of each stock option granted under the 2017 Plan shall be fixed by the Compensation Committee, but no stock options will be exercisable more than ten years after the grant date, or in the case of an ISO granted to a 10% stockholder, five years after the grant date. The exercise price of any ISO granted under the 2017 Plan to an individual who is not a 10% stockholder at the time of the grant shall not be less than the fair market value of the shares at the time of the grant, and the exercise price of any ISO granted to a 10% stockholder shall not be less than 110% of the fair market value at the time of grant.
Percentage held by stockholder									10.00%
Exercise price of option granted, percentage of fair market value									110.00%
Shares remaining available for issuance								27,500	27,500
2017 Stock Option Plan [Member] \| Ten Percent of Stockholder [Member]
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term									5 years
2017 Stock Option Plan [Member] \| Robert Ferguson [Member]
Common stock exercise price per share \| $ / shares								$ 3.65	$ 3.65
2017 Stock Option Plan [Member] \| Non-qualified Stock Options and Incentive Stock Options [Member]
Number of shares available for issuance								540,000	540,000
2017 Stock Option Plan [Member] \| Maximum [Member] \| Robert Ferguson [Member]
Option granted to purchase shares									100,000
2003 Outside Directors Stock Plan [Member] \| Employee [Member]
Shares granted from option exercise								18,000
Proceeds from exercise of stock options \| $								$ 79,000
2003 Outside Directors Stock Plan [Member] \| Two Previous Retired Outside Directors [Member]
Shares granted from option exercise								14,400
Proceeds from exercise of stock options \| $								$ 54,000
2003 Outside Directors Stock Plan [Member] \| Non-qualified Stock Options [Member] \| Five of Six Re-Elected Directors [Member]
Stock options granted vesting period		180 days
Option granted to purchase shares		12,000
Stock options, grants in period, exercise price \| $ / shares		$ 3.31
Stock options granted contractual term		10 years
2003 Outside Directors Stock Plan [Member] \| Non-qualified Stock Options [Member] \| New Director [Member]
Stock options granted vesting period							180 days
Option granted to purchase shares							6,000
Stock options, grants in period, exercise price \| $ / shares							$ 4.05
Stock options granted contractual term							10 years
2003 Outside Directors Stock Plan [Member] \| Non-qualified Stock Options [Member] \| Six Re-elected Directors [Member]
Stock options granted vesting period					180 days
Option granted to purchase shares					12,000
Stock options, grants in period, exercise price \| $ / shares					$ 4.30
Stock options granted contractual term					10 years
2017 Plan [Member] \| Incentive Stock Options [Member] \| Employee [Member]
Stock options granted vesting period	5 years
Option granted to purchase shares	12,500
Stock options, grants in period, exercise price \| $ / shares	$ 3.90
Stock options granted contractual term	6 years
2003 Outside Directors Stock Option Plan [Member]
Percentage of directors fees, description									As a member of the Board, each director elects to receive either 65% or 100% of the director's fee in shares of our Common Stock. The number of shares received is calculated based on 75% of the fair market value of our Common Stock determined on the business day immediately preceding the date that the quarterly fee is due.
Stock issued during period for services, shares									71,905
2003 Outside Directors Stock Option Plan [Member]
Stock issued during period for services, shares										60,598
The 2003 Outside Directors Stock Plan [Member] \| Portion of Director Fee Earned in Common Stock [Member]
Allocated share-based compensation expense \| $									$ 232,000	$ 249,000