Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v3.19.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2018
Apr. 01, 2019
Jun. 30, 2018
Document and Entity Information [Abstract]      
Entity Registrant Name KBL MERGER CORP. IV    
Entity Central Index Key 0001690080    
Trading Symbol KBLM    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Type 10-K    
Document Period End Date Dec. 31, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Filer Category Accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
Entity Shell Company true    
Entity Public Float     $ 114,310,000
Entity Common Stock, Shares Outstanding   9,748,977