Document and Entity Information - shares	6 Months Ended
	Jul. 01, 2017	Jul. 21, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	MUELLER INDUSTRIES INC
Entity Central Index Key	0000089439
Current Fiscal Year End Date	--12-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jul. 01, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		57,627,171