Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 09, 2019
Document and Entity Information [Abstract]    
Entity Registrant Name KBL MERGER CORP. IV  
Entity Central Index Key 0001690080  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Type 10-Q  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Entity Filer Category Accelerated Filer  
Entity Ex Transition Period false  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Current reporting Status Yes  
Entity Shell Company true  
Entity File Number 001-38105  
Entity Interactive Data Current Yes  
Entity Incorporation State Country Code DE  
Entity Common Stock, Shares Outstanding   8,168,215