Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
8 Months Ended
Sep. 30, 2020
Nov. 02, 2020
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2020  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q3  
Entity Registrant Name GigCapital3, Inc.  
Entity Central Index Key 0001802749  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Common Stock, Shares Outstanding   25,893,479
Entity Shell Company true  
Entity File Number 001-39283  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 84-4605714  
Entity Address, Address Line One 1731 Embarcadero Rd.  
Entity Address, Address Line Two Suite 200  
Entity Address, City or Town Palo Alto  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94303  
City Area Code (650)  
Local Phone Number 276-7040  
Document Quarterly Report true  
Document Transition Report false  
Common Stock    
Document Information [Line Items]    
Title of 12(b) Security Units, each consisting of one share of Common Stock and three-fourths of one Redeemable Warrant  
Trading Symbol GIK.U  
Security Exchange Name NYSE  
Document Information [Line Items]    
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Trading Symbol GIK  
Security Exchange Name NYSE  
Document Information [Line Items]    
Title of 12(b) Security Redeemable Warrants, each full warrant exercisable for one share of Common Stock at an exercise price of $11.50 per share  
Trading Symbol GIK.WS  
Security Exchange Name NYSE