Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 28, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Registrant Name	IMAGE SENSING SYSTEMS INC
Entity Central Index Key	0000943034
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 15,979,542
Entity Common Stock, Shares Outstanding		5,279,485
Entity Shell Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true