Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 20, 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	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		57,805,254