Basis of Presentation	9 Months Ended
Sep. 30, 2017
Nature Of Business And Significant Accounting Policies [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, 2016, 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 September 30, 2017 and for the three and nine-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 make them easier to use, with the ultimate 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. Fair Value Measurements The carrying value of trade receivables, accounts payable, and other financial working capital items approximates fair value at September 30, 2017 and December 31, 2016, 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. 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.

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, 2016, 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 September 30, 2017 and for the three and nine-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 make them easier to use, with the ultimate 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.

Fair Value Measurements

The carrying value of trade receivables, accounts payable, and other financial working capital items approximates fair value at September 30, 2017 and December 31, 2016, 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.

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.