v3.10.0.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 29, 2018
Feb. 02, 2019
Jun. 30, 2018
Document and Entity Information [Abstract]      
Entity Registrant Name UNIVERSAL FOREST PRODUCTS INC    
Entity Central Index Key 0000912767    
Current Fiscal Year End Date --12-29    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding (in shares)   60,890,762  
Entity Public Float     $ 2,136,389,121
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 29, 2018    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false