Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

v3.21.1
Document And Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2020
Mar. 01, 2021
Jun. 30, 2020
Document Type 10-K    
Document Annual Report true    
Current Fiscal Year End Date --12-31    
Document Period End Date Dec. 31, 2020    
Document Fiscal Year Focus 2020    
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     $ 36,646,000
Entity Common Stock, Shares Outstanding   9,327,574  
Documents Incorporated by Reference
The information required by Part III of Form 10-K will either be (i) incorporated by reference from portions of the Company’s definitive proxy statement for its 2021 Annual Meeting of Shareholders, or (ii) included in an amendment to this Form10-K on Form 10-K/A, in either case within 120 days of December 31, 2020.
   
Amendment Flag false    
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