XML 13 R1.htm IDEA: XBRL DOCUMENT v3.19.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2019
May 14, 2019
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Entity Registrant Name CLEARSIGN COMBUSTION CORP  
Entity Central Index Key 0001434524  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Trading Symbol CLIR  
Entity Common Stock, Shares Outstanding   26,699,761
Entity Emerging Growth Company false  
Entity Small Business true