Cover Page - USD ($)	12 Months Ended
	Dec. 26, 2020	Feb. 19, 2021	Jun. 27, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 26, 2020
Current Fiscal Year End Date	--12-26
Document Transition Report	false
Entity File Number	1-6770
Entity Registrant Name	MUELLER INDUSTRIES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	25-0790410
Entity Address, Address Line One	150 Schilling Boulevard
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Collierville
Entity Address, State or Province	TN
Entity Address, Postal Zip Code	38017
City Area Code	901
Local Phone Number	753-3200
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	MLI
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,346,053,993
Entity Common Stock, Shares Outstanding		57,115,648
Documents Incorporated by Reference	Portions of the following document are incorporated by reference into this Report: Registrant’s Definitive Proxy Statement for the 2021 Annual Meeting of Stockholders, scheduled to be mailed on or about March 25, 2021 (Part III).
Entity Central Index Key	0000089439
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false