Basis of Presentation	6 Months Ended
Jun. 30, 2019
Basis of Presentation [Abstract]
Basis of Presentation	Note 1. Basis of Presentation The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with the instructions and regulations of the Securities and Exchange Commission to Form 10-Q. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for complete financial statements. This report should be read together with the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, including the audited financial statements and footnotes therein. Management believes that the unaudited financial statements include all adjustments, consisting of normal recurring accruals, necessary to fairly state the financial position and results of operations as of June 30, 2019 and for the three and six-month periods then ended in accordance with accounting principles generally accepted in the United States of America. The results of interim periods may not be indicative of results to be expected for the year. Nature of Business Electro-Sensors, Inc. manufactures and markets a complete line of monitoring and control systems for a variety of industrial machinery. The Company uses leading-edge technology to continuously improve its products and expand the number of applications they can be used in, with the goal of manufacturing the industry-preferred product for every market served. The Company sells these products through an internal sales staff, manufacturers’ representatives, and distributors to a wide variety of industries that use the products in a variety of applications to monitor process machinery operations. The Company markets its products to customers located throughout the United States, Canada, Latin America, Europe, and Asia. Revenue Recognition At contract inception, the Company assesses the goods and services promised to a customer and identifies a performance obligation for each distinct promised good or service. We also determine the transaction price for each performance obligation at contract inception. Our contracts, generally in the form of a purchase order, specify the product or service that is promised to the customer. The typical contract life is less than one month and contains a single performance obligation, to provide conforming goods or services to the customer. On some contracts, we have a second performance obligation which, typically, is the initialization of the HazardPRO product. For contracts that have multiple performance obligations, we allocate the transaction price to each performance obligation using the relative stand-alone selling price. We generally determine stand-alone selling prices based on the observable stand-alone prices charged to customers. We recognize product revenue at the point in time when control of the product is transferred to the customer, which typically occurs when we ship the products. We recognize service revenue at the point in time when we have provided the service. Fair Value Measurements The carrying value of trade receivables, accounts payable, and other financial working capital items approximates fair value at June 30, 2019 and December 31, 2018, due to the short maturity nature of these instruments. Stock-Based Compensation The Company records compensation expense for stock options based on the estimated fair value of the options on the date of grant using the Black-Scholes-Merton (“BSM”) option pricing model. The Company uses historical data, among other factors, to estimate the expected price volatility, the expected option life, and the expected forfeiture rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the estimated life of the option. As of June 30, 2019, there was approximately $20 of unrecognized compensation expense related to unvested stock options. The Company expects to recognize this expense over the next three years. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Significant estimates, including the underlying assumptions, consist of economic lives of long-lived assets, realizability of trade receivables, valuation of deferred tax assets/liabilities, inventory, investments, contingent earn-out, and stock compensation expense. It is at least reasonably possible that these estimates may change in the near term. Net Income (Loss) per Common Share Basic and diluted net income (loss) per common share is determined by dividing net income (loss) attributable to common stockholders by the weighted-average common shares outstanding during the period. For the three and six-month periods ended June 30, 2019 and 2018, the common shares underlying stock options have been excluded from the calculation because their effect would be anti-dilutive. Therefore, the weighted-average shares outstanding used to calculate both basic and diluted loss per common shares are the same. For the three and six months ended June 30, 2019 and 2018 options to purchase 295,000 and 287,500 weighted average common shares, respectively, have been excluded from the computations of diluted weighted-average shares outstanding because their effect would be anti-dilutive.

Note 1. Basis of Presentation

The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with the instructions and regulations of the Securities and Exchange Commission to Form 10-Q. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for complete financial statements.

This report should be read together with the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, including the audited financial statements and footnotes therein.

Management believes that the unaudited financial statements include all adjustments, consisting of normal recurring accruals, necessary to fairly state the financial position and results of operations as of June 30, 2019 and for the three and six-month periods then ended in accordance with accounting principles generally accepted in the United States of America. The results of interim periods may not be indicative of results to be expected for the year.

Nature of Business

Electro-Sensors, Inc. manufactures and markets a complete line of monitoring and control systems for a variety of industrial machinery. The Company uses leading-edge technology to continuously improve its products and expand the number of applications they can be used in, with the goal of manufacturing the industry-preferred product for every market served. The Company sells these products through an internal sales staff, manufacturers’ representatives, and distributors to a wide variety of industries that use the products in a variety of applications to monitor process machinery operations. The Company markets its products to customers located throughout the United States, Canada, Latin America, Europe, and Asia.

Revenue Recognition

At contract inception, the Company assesses the goods and services promised to a customer and identifies a performance obligation for each distinct promised good or service. We also determine the transaction price for each performance obligation at contract inception. Our contracts, generally in the form of a purchase order, specify the product or service that is promised to the customer. The typical contract life is less than one month and contains a single performance obligation, to provide conforming goods or services to the customer. On some contracts, we have a second performance obligation which, typically, is the initialization of the HazardPRO product. For contracts that have multiple performance obligations, we allocate the transaction price to each performance obligation using the relative stand-alone selling price. We generally determine stand-alone selling prices based on the observable stand-alone prices charged to customers. We recognize product revenue at the point in time when control of the product is transferred to the customer, which typically occurs when we ship the products. We recognize service revenue at the point in time when we have provided the service.

Fair Value Measurements

The carrying value of trade receivables, accounts payable, and other financial working capital items approximates fair value at June 30, 2019 and December 31, 2018, due to the short maturity nature of these instruments.

Stock-Based Compensation

The Company records compensation expense for stock options based on the estimated fair value of the options on the date of grant using the Black-Scholes-Merton (“BSM”) option pricing model. The Company uses historical data, among other factors, to estimate the expected price volatility, the expected option life, and the expected forfeiture rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the estimated life of the option.

As of June 30, 2019, there was approximately $20 of unrecognized compensation expense related to unvested stock options. The Company expects to recognize this expense over the next three years.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Significant estimates, including the underlying assumptions, consist of economic lives of long-lived assets, realizability of trade receivables, valuation of deferred tax assets/liabilities, inventory, investments, contingent earn-out, and stock compensation expense. It is at least reasonably possible that these estimates may change in the near term.

Net Income (Loss) per Common Share

Basic and diluted net income (loss) per common share is determined by dividing net income (loss) attributable to common stockholders by the weighted-average common shares outstanding during the period. For the three and six-month periods ended June 30, 2019 and 2018, the common shares underlying stock options have been excluded from the calculation because their effect would be anti-dilutive. Therefore, the weighted-average shares outstanding used to calculate both basic and diluted loss per common shares are the same.

For the three and six months ended June 30, 2019 and 2018 options to purchase 295,000 and 287,500 weighted average common shares, respectively, have been excluded from the computations of diluted weighted-average shares outstanding because their effect would be anti-dilutive.