Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v3.10.0.1
Document and Entity Information - USD ($)
12 Months Ended
Sep. 30, 2018
Nov. 30, 2018
Mar. 30, 2018
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Sep. 30, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Registrant Name GigCapital, Inc.    
Entity Central Index Key 0001719489    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Accelerated Filer    
Trading Symbol GIG    
Entity Small Business true    
Entity Shell Company true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
Entity Common Stock, Shares Outstanding   18,462,006  
Entity Public Float     $ 180,373,799