CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Income Statement [Abstract]
Net sales	$ 608,602	$ 645,958	$ 1,886,777	$ 1,948,791
Cost of goods sold	510,788	566,956	1,586,129	1,676,446
Depreciation and amortization	10,823	10,619	31,856	29,081
Selling, general, and administrative expense	40,739	38,889	121,838	112,077
Gain on sale of assets	0	(2,691)	0	(334)
Insurance recovery	0	(1,486)	0	(1,486)
Operating income	46,252	33,671	146,954	133,007
Interest expense	(6,148)	(6,746)	(20,135)	(18,728)
Other income, net	533	411	823	1,557
Income before income taxes	40,637	27,336	127,642	115,836
Income tax expense	(7,665)	(3,373)	(27,643)	(23,179)
Loss from unconsolidated affiliates, net of foreign tax	(2,528)	(3,100)	(23,740)	(13,568)
Consolidated net income	30,444	20,863	76,259	79,089
Net income attributable to noncontrolling interests	(1,351)	(571)	(3,457)	(1,487)
Net income attributable to Mueller Industries, Inc.	$ 29,093	$ 20,292	$ 72,802	$ 77,602
Weighted average shares for basic earnings per share (in shares)	55,832	56,877	55,771	56,858
Effect of dilutive stock-based awards (in shares)	482	540	523	524
Adjusted weighted average shares for diluted earnings per share (in shares)	56,314	57,417	56,294	57,382
Basic earnings per share (in dollars per share)	$ 0.52	$ 0.36	$ 1.31	$ 1.36
Diluted earnings per share (in dollars per share)	0.52	0.35	1.29	1.35
Dividends per share (in dollars per share)	$ 0.10	$ 0.10	$ 0.30	$ 0.30