Document and Entity Information
6 Months Ended
Jun. 29, 2019
Document and Entity Information [Abstract]  
Document Type 10-Q
Document Quarterly Report true
Document Transition Report false
Document Period End Date Jun. 29, 2019
Entity File Number 0-22684
Entity Incorporation, State or Country Code MI
Entity Tax Identification Number 38-1465835
Entity Address, Address Line One 2801 East Beltline NE
Entity Address, City or Town Grand Rapids
Entity Address, State or Province MI
Entity Address, Postal Zip Code 49525
City Area Code 616
Local Phone Number 364-6161
Title of 12(b) Security Common Stock
Trading Symbol UFPI
Security Exchange Name NASDAQ
Entity Current Reporting Status Yes
Entity Interactive Data Current Yes
Entity Filer Category Large Accelerated Filer
Entity Small Business false
Entity Emerging Growth Company false
Entity Shell Company false
Entity Common Stock, Shares Outstanding (in shares) 61,366,680
Current Fiscal Year End Date --12-28
Document Fiscal Year Focus 2019
Document Fiscal Period Focus Q2
Entity Central Index Key 0000912767
Amendment Flag false