Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

v3.20.1
Document And Entity Information - shares
 3 Months Ended
Mar. 31, 2020
May 01, 2020
Document and Entity Information [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Current Fiscal Year End Date --12-31  
Document Period End Date Mar. 31, 2020  
Document Fiscal Year Focus 2020  
Document Transition Report false  
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 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  
Title of 12(b) Security Common Stock, par value , $.05 per share  
Trading Symbol JCS  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding   9,351,486
Amendment Flag false  
Document Fiscal Period Focus Q1  
Entity Central Index Key 0000022701