Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

v3.20.1
Document And Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2019
Mar. 01, 2020
Jun. 30, 2019
Document Type 10-K/A    
Document Annual Report true    
Current Fiscal Year End Date --12-31    
Document Period End Date Dec. 31, 2019    
Document Fiscal Year Focus 2019    
Entity File Number 001-31588    
Entity Registrant Name COMMUNICATIONS SYSTEMS INC    
Entity Incorporation, State or Country Code MN    
Entity Tax Identification Number 41-0957999    
Entity Address, Address Line One 10900 Red Circle Drive    
Entity Address, City or Town Minnetonka    
Entity Address, State or Province MN    
Entity Address, Postal Zip Code 55343    
City Area Code 952    
Local Phone Number 996-1674    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 21,641,000
Entity Common Stock, Shares Outstanding   9,256,298  
Documents Incorporated by Reference
Portions of the Company’s Proxy Statement for its Annual Meeting of Shareholders to be held on June 17, 2020 are incorporated by reference into Part III of this Form 10-K.
   
Amendment Flag true    
Amendment Description On March 17, 2020, Communications Systems, Inc. ("Company") filed its Annual Report on Form 10-K for the year ended December 31, 2019. After filing, the Company discovered that the XBRL links in the Form 10-K were not operative. Therefore, the Company is filing this Amendment No. 1 to Form 10-K on Form 10-K/A to correct these links. There are no other substantive changes in this Amendment No. 1 to Form 10-K on Form 10-K/A to the original Form 10-K filing.    
Document Fiscal Period Focus FY    
Entity Central Index Key 0000022701    
Common Stock [Member]      
Title of 12(b) Security Common Stock, $.05 par value    
Trading Symbol JCS    
Security Exchange Name NASDAQ    
Preferred Stock [Member]      
Title of 12(b) Security Preferred Stock Purchase Rights