Annual report pursuant to Section 13 and 15(d)

Cover Page

v3.22.0.1
Cover Page - USD ($)
$ in Millions
 12 Months Ended
Jan. 01, 2022
Mar. 11, 2022
Jun. 26, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Jan. 01, 2022    
Current Fiscal Year End Date --01-01    
Document Transition Report false    
Entity File Number 001-04321    
Entity Registrant Name JANUS INTERNATIONAL GROUP, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 86-1476200    
Entity Address, Address Line One 135 Janus International Blvd.    
Entity Address, City or Town Temple    
Entity Address, State or Province GA    
Entity Address, Postal Zip Code 30179    
City Area Code 866    
Local Phone Number 562-2580    
Title of 12(b) Security Common Stock, par value $0.0001 per share    
Trading Symbol JBI    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
ICFR Auditor Attestation Flag false    
Entity Shell Company false    
Entity Public Float     $ 879.3
Entity Common Stock, Shares Outstanding   146,561,717  
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Central Index Key 0001839839