Document and Entity Information	3 Months Ended
	Mar. 30, 2019 shares
Document and Entity Information [Abstract]
Entity Registrant Name	UNIVERSAL FOREST PRODUCTS INC
Entity Central Index Key	0000912767
Current Fiscal Year End Date	--12-28
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)	61,352,372
Entity Current Reporting Status	Yes
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 30, 2019
Entity Small Business	false
Entity Emerging Growth Company	false