Mueller Industries (MLI) 10-Q 21 Jul 21 2021 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 26, 2021	Jul. 16, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 26, 2021
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
Trading Symbol	MLI
Security Exchange Name	NYSE
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		57,153,791
Entity Central Index Key	0000089439
Current Fiscal Year End Date	--12-25
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Income Statement [Abstract]
Net sales	$ 1,012,592	$ 500,168	$ 1,830,740	$ 1,103,087
Cost of goods sold	799,712	403,159	1,468,130	911,874
Depreciation and amortization	11,134	11,097	22,889	22,136
Selling, general, and administrative expense	43,932	33,616	89,367	76,368
Asset impairments	0	0	0	3,035
Litigation settlement, net	0	0	0	(21,933)
Operating income	157,814	52,296	250,354	111,607
Interest expense	(1,866)	(4,973)	(6,335)	(10,352)
Redemption premium	(5,674)	0	(5,674)	0
Other income, net	683	2,834	1,260	3,112
Income before income taxes	150,957	50,157	239,605	104,367
Income tax expense	(39,006)	(13,029)	(60,767)	(27,173)
Loss from unconsolidated affiliates, net of foreign tax	(1,019)	(8,641)	(2,668)	(14,756)
Consolidated net income	110,932	28,487	176,170	62,438
Net income attributable to noncontrolling interests	(2,100)	(531)	(4,231)	(2,067)
Net income attributable to Mueller Industries, Inc.	$ 108,832	$ 27,956	$ 171,939	$ 60,371
Weighted average shares for basic earnings per share (in shares)	55,946	55,723	55,931	55,799
Effect of dilutive stock-based awards (in shares)	866	471	811	527
Adjusted weighted average shares for diluted earnings per share (in shares)	56,812	56,194	56,742	56,326
Basic earnings per share (in dollars per share)	$ 1.95	$ 0.50	$ 3.07	$ 1.08
Diluted earnings per share (in dollars per share)	1.92	0.50	3.03	1.07
Dividends per share (in dollars per share)	$ 0.13	$ 0.10	$ 0.26	$ 0.20

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Statement of Comprehensive Income [Abstract]
Consolidated net income	$ 110,932	$ 28,487	$ 176,170	$ 62,438
Other comprehensive (loss) income, net of tax:
Foreign currency translation	3,515	421	7,902	(20,834)
Net change with respect to derivative instruments and hedging activities, net of tax of $961, $(970), $814, and $(10)	(3,337)	3,398	(2,844)	41
Net change in pension and postretirement obligation adjustments, net of tax of $1, $375, $57, and $132	74	(1,284)	(17)	(545)
Attributable to unconsolidated affiliates, net of tax of $219, $810, $(358), and $262	(753)	(2,790)	1,234	(903)
Total other comprehensive (loss) income, net	(501)	(255)	6,275	(22,241)
Consolidated comprehensive income	110,431	28,232	182,445	40,197
Comprehensive (income) loss attributable to noncontrolling interests	(1,333)	90	(3,885)	(855)
Comprehensive income attributable to Mueller Industries, Inc.	$ 109,098	$ 28,322	$ 178,560	$ 39,342

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Statement of Comprehensive Income [Abstract]
Net change with respect to derivative instruments and hedging activities, tax (expense) benefit	$ 961	$ (970)	$ 814	$ (10)
Net actuarial loss on pension and postretirement obligations, tax benefit (expense)	1	375	57	132
Attributable to unconsolidated affiliates, tax benefit (expense)	$ 219	$ 810	$ (358)	$ 262

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Current assets:
Cash and cash equivalents	$ 110,681	$ 119,075
Accounts receivable, less allowance for doubtful accounts of $2,818 in 2021 and $1,538 in 2020	542,044	357,532
Inventories	384,982	315,002
Other current assets	44,288	33,752
Total current assets	1,081,995	825,361
Property, plant, and equipment, net	385,246	376,572
Operating lease right-of-use assets	26,871	29,301
Goodwill, net	169,364	167,764
Intangible assets, net	76,886	77,207
Investments in unconsolidated affiliates	36,899	37,976
Other assets	12,176	14,387
Total assets	1,789,437	1,528,568
Current liabilities:
Current portion of debt	6,428	41,283
Accounts payable	190,403	147,741
Accrued wages and other employee costs	39,502	46,299
Current portion of operating lease liabilities	6,546	6,259
Other current liabilities	119,550	98,061
Total current liabilities	362,429	339,643
Long-term debt, less current portion	350,996	286,593
Pension liabilities	11,799	13,552
Postretirement benefits other than pensions	13,368	13,289
Environmental reserves	21,020	21,256
Deferred income taxes	16,363	16,842
Noncurrent operating lease liabilities	19,433	21,602
Other noncurrent liabilities	20,113	14,731
Total liabilities	815,521	727,508
Mueller Industries, Inc. stockholders' equity:
Preferred stock - $1.00 par value; shares authorized 5,000,000; none outstanding	0	0
Common stock - $.01 par value; shares authorized 100,000,000; issued 80,183,004; outstanding 57,151,341 in 2021 and 57,087,432 in 2020	802	802
Additional paid-in capital	285,148	280,051
Retained earnings	1,176,812	1,019,694
Accumulated other comprehensive loss	(48,262)	(54,883)
Treasury common stock, at cost	(468,784)	(468,919)
Total Mueller Industries, Inc. stockholders' equity	945,716	776,745
Noncontrolling interests	28,200	24,315
Total equity	973,916	801,060
Commitments and contingencies	0	0
Total liabilities and equity	$ 1,789,437	$ 1,528,568

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 2,818	$ 1,538
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	80,183,004	80,183,004
Common stock, shares outstanding (in shares)	57,151,341	57,087,432

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020
Cash flows from operating activities
Consolidated net income	$ 176,170	$ 62,438
Reconciliation of consolidated net income to net cash provided by operating activities:
Depreciation and amortization	22,975	22,296
Stock-based compensation expense	4,817	4,198
Provision for doubtful accounts receivable	1,280	1,850
Loss from unconsolidated affiliates	2,668	14,756
Redemption premium	5,674	0
Gain on disposals of properties	(819)	(9)
Impairment charges	0	3,035
Deferred income tax expense	3,252	764
Changes in assets and liabilities, net of effects of businesses acquired:
Receivables	(190,944)	(11,212)
Inventories	(63,949)	43,263
Other assets	(5,482)	3,967
Current liabilities	50,456	(277)
Other liabilities	3,429	(5,369)
Other, net	(247)	3,082
Net cash provided by operating activities	9,280	142,782
Cash flows from investing activities
Capital expenditures	(17,978)	(22,215)
Acquisition of businesses, net of cash acquired	(13,935)	(15,415)
Payment received for notes receivable	8,539	0
Proceeds from sales of assets	1,730	1
Net cash used in investing activities	(21,644)	(37,629)
Cash flows from financing activities
Dividends paid to stockholders of Mueller Industries, Inc.	(14,546)	(11,168)
Repurchase of common stock	0	(5,574)
Issuance of debt	425,000	110,015
Repayments of debt	(400,497)	(166,021)
Issuance (repayment) of debt by consolidated joint ventures, net	463	(471)
Net cash received to settle stock-based awards	414	696
Debt issuance costs	(1,111)	0
Net cash provided by (used in) financing activities	9,723	(72,523)
Effect of exchange rate changes on cash	987	(6,160)
(Decrease) increase in cash, cash equivalents, and restricted cash	(1,654)	26,470
Cash, cash equivalents, and restricted cash at the beginning of the period	127,376	98,042
Cash, cash equivalents, and restricted cash at the end of the period	$ 125,722	$ 124,512

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Balance at beginning of period at Dec. 28, 2019		$ 802	$ 278,609	$ 903,070	$ (68,770)	$ (470,243)	$ 18,668
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Acquisition (issuance) of shares under incentive stock option plans			(667)			1,363
Stock-based compensation expense			4,198
Issuance of restricted stock			(284)			284
Net income attributable to Mueller Industries, Inc.	$ 60,371			60,371
Dividends paid or payable to stockholders of Mueller Industries, Inc.				(11,449)
Total other comprehensive income (loss) attributable to Mueller Industries, Inc.	(22,241)				(21,029)
Repurchase of common stock						(5,574)
Net income attributable to noncontrolling interests	(2,067)						2,067
Foreign currency translation	(20,834)						(1,212)
Balance at end of period at Jun. 27, 2020		802	281,856	951,992	(89,799)	(474,170)	19,523
Balance at beginning of period at Mar. 28, 2020		802	280,197	929,810	(90,165)	(474,957)	19,613
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Acquisition (issuance) of shares under incentive stock option plans			(270)			503
Stock-based compensation expense			2,213
Issuance of restricted stock			(284)			284
Net income attributable to Mueller Industries, Inc.	27,956			27,956
Dividends paid or payable to stockholders of Mueller Industries, Inc.				(5,774)
Total other comprehensive income (loss) attributable to Mueller Industries, Inc.	(255)				366
Repurchase of common stock						0
Net income attributable to noncontrolling interests	(531)						531
Foreign currency translation	421						(621)
Balance at end of period at Jun. 27, 2020		802	281,856	951,992	(89,799)	(474,170)	19,523
Balance at beginning of period at Dec. 26, 2020	801,060	802	280,051	1,019,694	(54,883)	(468,919)	24,315
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Acquisition (issuance) of shares under incentive stock option plans			565			(124)
Stock-based compensation expense			4,817
Issuance of restricted stock			(285)			285
Net income attributable to Mueller Industries, Inc.	171,939			171,939
Dividends paid or payable to stockholders of Mueller Industries, Inc.				(14,821)
Total other comprehensive income (loss) attributable to Mueller Industries, Inc.	6,275				6,621
Repurchase of common stock						(26)
Net income attributable to noncontrolling interests	(4,231)						4,231
Foreign currency translation	7,902						(346)
Balance at end of period at Jun. 26, 2021	973,916	802	285,148	1,176,812	(48,262)	(468,784)	28,200
Balance at beginning of period at Mar. 27, 2021		802	282,713	1,075,410	(48,528)	(469,251)	26,867
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Acquisition (issuance) of shares under incentive stock option plans			12			182
Stock-based compensation expense			2,708
Issuance of restricted stock			(285)			285
Net income attributable to Mueller Industries, Inc.	108,832			108,832
Dividends paid or payable to stockholders of Mueller Industries, Inc.				(7,430)
Total other comprehensive income (loss) attributable to Mueller Industries, Inc.	(501)				266
Repurchase of common stock						0
Net income attributable to noncontrolling interests	(2,100)						2,100
Foreign currency translation	3,515						(767)
Balance at end of period at Jun. 26, 2021	$ 973,916	$ 802	$ 285,148	$ 1,176,812	$ (48,262)	$ (468,784)	$ 28,200

Recent Accounting Standards

Recent Accounting Standards	6 Months Ended
	Jun. 26, 2021
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standards	Recent Accounting Standards Adopted In October 2020, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2020-10, Codification Improvements: An Amendment of the FASB Accounting Standards Codification . The ASU facilitates updates to the Accounting Standards Codification for technical corrections such as conforming amendments, clarifications to guidance, simplifications to wording or structure of guidance, and other minor improvements. The Company adopted the ASU during the first quarter of 2021 using a retrospective approach. The adoption of the ASU did not have a material impact on the Company’s Condensed Consolidated Financial Statements. In January 2020, the FASB issued ASU No. 2020-01, Investments - Equity Securities (Topic 321), Investments - Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815): Clarifying the Interactions between Topic 321, Topic 323, and Topic 815 . The new guidance addresses accounting for the transition into and out of the equity method and measuring certain purchased options and forward contracts to acquire investments. The Company adopted the ASU during the first quarter of 2021 using a prospective approach. The adoption of the ASU did not have a material impact on the Company’s Condensed Consolidated Financial Statements. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes . The new guidance affects general principles within Topic 740, Income Taxes. The amendments of ASU 2019-12 are meant to simplify and reduce the cost of accounting for income taxes. The Company adopted the ASU during the first quarter of 2021 using a prospective approach. The adoption of the ASU did not have a material impact on the Company’s Condensed Consolidated Financial Statements. Issued In January 2021, the FASB issued ASU No. 2021-01, Reference Rate Reform (Topic 848): An Amendment of the FASB Accounting Standards Codification. The new guidance was issued in response to concerns about structural risks of interbank offered rates, and, particularly, the risk of cessation of the London Interbank Offered Rate (LIBOR). Regulators in numerous jurisdictions around the world have undertaken reference rate reform initiatives to identify alternative reference rates that are more observable or transaction based and less susceptible to manipulation. The ASU is effective in 2021 but can be applied through December 31, 2022. The updated guidance requires retrospective adoption, and early adoption is permitted. The Company does not expect the adoption of the ASU to have a material impact on its Condensed Consolidated Financial Statements.

Earnings per Common Share

Earnings per Common Share	6 Months Ended
	Jun. 26, 2021
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common Share Basic per share amounts have been computed based on the average number of common shares outstanding. Diluted per share amounts reflect the increase in average common shares outstanding that would re sult from the assumed exercise of outstanding stock options and vesting of restricted stock awards, computed using the treasury stock method. Approximately five thousand and eight thousand stock-based awards were excluded from the computation of diluted earnings per share for the quarters ended June 26, 2021 and June 27, 2020, respectively, because they were antidilutive.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 26, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Acquisitions H&C Flex On December 20, 2020, the Company entered into an asset purchase agreement with Hart & Cooley LLC. The transaction closed on January 29, 2021, whereby the Company purchased the Hart & Cooley flexible duct business, which included inventory, manufacturing equipment, and related assets for approximately $15.4 million. The total purchase price consisted of $14.0 million in cash paid at closing and a contingent consideration arrangement currently estimated at $1.4 million. The Company treated this as a business combination. The acquired business, H&C Flex, is a manufacturer and distributor of insulated HVAC flexible duct systems. It is reported within and complements the Company’s existing businesses in the Climate segment. As of June 26, 2021, the provisional fair value of tangible assets acquired totaled $15.3 million, consisting primarily of property, plant, and equipment of $10.8 million and inventory of $4.5 million. Of the remaining purchase price, $0.1 million was allocated to tax-deductible goodwill. During the second quarter of 2021, there was a change in the valuation that resulted in an increase in property, plant, and equipment of $2.4 million, a decrease in goodwill of $1.0 million, and the recognition of contingent consideration of $1.4 million. The purchase price allocation is provisional as of June 26, 2021 and subject to change upon completion of the final valuation of the assets and contingent consideration during the measurement period. Kessler Sales and Distribution, LLC On August 3, 2020, the Company entered into an asset purchase agreement with Wieland-Kessler LLC, whereby the Company purchased the Kessler distribution business, which included inventory, manufacturing equipment, and related assets. The total purchase price was $57.2 million in cash paid at closing. The Company treated this as a business combination. The acquired business, Kessler Sales and Distribution, LLC, is a distributor of residential and commercial plumbing products. It is reported within and complements the Company’s existing businesses in the Piping Systems segment. The provisional fair value of tangible assets acquired totaled $27.3 million, consisting primarily of inventory. Of the remaining purchase price, $29.9 million was allocated to tax-deductible goodwill and intangible assets. During the second quarter of 2021, there was a change in the valuation that resulted in a decrease in property, plant, and equipment and an increase in goodwill of $1.4 million. During the first quarter of 2021, there was a change in the valuation that resulted in a decrease in goodwill and an increase in intangible assets of $1.5 million. The purchase price allocation is provisional as of June 26, 2021 and subject to change upon completion of the final valuation of the long-lived assets during the measurement period. Shoals Tubular, Inc. On January 17, 2020, the Company entered into a stock purchase agreement pursuant to which the Company acquired all of the outstanding stock of Shoals Tubular, Inc. (STI) for approximately $15.3 million, net of working capital adjustments. The total purchase price consisted of $15.3 million in cash at closing. STI is a manufacturer of brazed manifolds, headers, and distributor assemblies used primarily by manufacturers of residential heating and air conditioning units. The acquired business is reported within and complements the Company’s existing businesses in the Climate segment. The fair value of the tangible assets acquired totaled $6.2 million, consisting primarily of property, plant, and equipment of $3.7 million, inventories of $1.8 million, and accounts receivable of $0.7 million. The fair value of the liabilities assumed totaled $0.2 million, consisting primarily of accounts payable. Of the remaining purchase price, $9.3 million was allocated to tax-deductible goodwill and intangible assets. The valuation of the business has been finalized. There were no material changes to the purchase price allocation from the amounts presented in the Company’s 2020 Annual Report on Form 10-K.

Segment Information

Segment Information	6 Months Ended
	Jun. 26, 2021
Segment Reporting [Abstract]
Segment Information	Segment InformationEach of the Company’s reportable segments is composed of certain operating segments that are aggregated primarily by the nature of products offered as follows: Piping Systems Piping Systems is composed of the following operating segments: Domestic Piping Systems Group, Great Lakes Copper, Heatlink Group, Die-Mold, European Operations, Trading Group, an d Jungwoo-Mueller (the Company’s South Korean joint venture). The Domestic Piping Systems Group manufactures and distributes copper tube, fittings, and line sets. These products are manufactured in the U.S., sold in the U.S., and exported to markets worldwide. Outside the U.S., Great Lakes Copper manufactures copper tube and line sets in Canada and sells the products primarily in the U.S. and Canada. Heatlink Group produces a complete line of products for PEX plumbing and radiant systems in Canada and sells these products in Canada and the U.S. Die-Mold manufactures PEX and other plumbing-related fittings and plastic injection tooling in Canada and sells these products in Canada and the U.S. European Operations manufactures copper tube in the U.K. which is sold primarily in Europe. The Trading Group manufactures pipe nipples and resells brass and plastic plumbing valves, malleable iron fittings, faucets, and plumbing specialty products in the U.S. and Mexico. Jungwoo-Mueller manufactures copper-based joining products that are sold worldwide. The Piping Systems segment’s products are sold primarily to plumbing, refrigeration, and air-conditioning wholesalers, hardware wholesalers and co-ops, building product retailers, and air-conditioning original equipment manufacturers (OEMs). Industrial Metals Industrial Metals is composed of the following operating segments: Brass Rod & Copper Bar Products, Impacts & Micro Gauge, and Brass Value-Added Products. These businesses manufacture brass rod, impact extrusions, and forgings, as well as a wide variety of end products including plumbing brass, automotive components, valves, fittings, and gas assemblies. These products are manufactured in the U.S. and sold primarily to OEMs in the U.S., many of which are in the industrial, transportation, construction, heating, ventilation, and air-conditioning, plumbing, refrigeration, and energy markets. Climate Climate is composed of the following operating segments: Refrigeration Products, Fabricated Tube Products, Westermeyer, Turbotec, Flex Duct , Linesets, Inc., and STI. These domestic businesses manufacture and fabricate valves, assemblies, high pressure components, coaxial heat exchangers, insulated HVAC flexible duct systems, line sets, brazed manifolds, headers, and distributor assemblies primarily for the heating, ventilation, air-conditioning, and refrigeration markets in the U.S. Summarized segment information is as follows: For the Quarter Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 711,616 $ 180,040 $ 131,708 $ (10,772) $ 1,012,592 Cost of goods sold 558,278 155,399 96,303 (10,268) 799,712 Depreciation and amortization 5,515 1,694 2,753 1,172 11,134 Selling, general, and administrative expense 23,315 2,448 7,280 10,889 43,932 Operating income 124,508 20,499 25,372 (12,565) 157,814 Interest expense (1,866) Redemption premium (5,674) Other income, net 683 Income before income taxes $ 150,957 Segment information (continued): For the Quarter Ended June 27, 2020 (In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 334,040 $ 88,619 $ 86,107 $ (8,598) $ 500,168 Cost of goods sold 272,271 75,274 64,540 (8,926) 403,159 Depreciation and amortization 5,456 1,995 2,757 889 11,097 Selling, general, and administrative expense 15,239 2,477 6,457 9,443 33,616 Operating income 41,074 8,873 12,353 (10,004) 52,296 Interest expense (4,973) Other income, net 2,834 Income before income taxes $ 50,157 For the Six Months Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 1,259,364 $ 344,892 $ 242,734 $ (16,250) $ 1,830,740 Cost of goods sold 1,008,632 296,290 180,385 (17,177) 1,468,130 Depreciation and amortization 11,725 3,437 5,382 2,345 22,889 Selling, general, and administrative expense 47,401 5,819 14,260 21,887 89,367 Operating income 191,606 39,346 42,707 (23,305) 250,354 Interest expense (6,335) Redemption premium (5,674) Other income, net 1,260 Income before income taxes $ 239,605 Segment information (continued): For the Six Months Ended June 27, 2020 ( In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 719,053 $ 219,821 $ 179,379 $ (15,166) $ 1,103,087 Cost of goods sold 591,435 190,071 135,633 (5,265) 911,874 Depreciation and amortization 11,155 3,997 5,223 1,761 22,136 Selling, general, and administrative expense 35,678 5,698 13,156 21,836 76,368 Asset impairments 3,035 — — — 3,035 Litigation settlement, net — — — (21,933) (21,933) Operating income 77,750 20,055 25,367 (11,565) 111,607 Interest expense (10,352) Other income, net 3,112 Income before income taxes $ 104,367 The following table presents total assets attributable to each segment: (In thousands) June 26, 2021 December 26, 2020 Segment assets: Piping Systems $ 1,222,336 $ 977,937 Industrial Metals 173,227 152,683 Climate 272,318 258,668 General Corporate 121,556 139,280 $ 1,789,437 $ 1,528,568 The following tables represent a disaggregation of revenue from contracts with customers, along with the reportable segment for each category: For the Quarter Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings $ 567,092 $ — $ — $ 567,092 Brass rod and forgings — 142,974 — 142,974 OEM components, tube & assemblies 8,456 12,710 43,449 64,615 Valves and plumbing specialties 136,068 — — 136,068 Flex duct and other HVAC components — — 88,259 88,259 Other — 24,356 — 24,356 711,616 180,040 131,708 1,023,364 Intersegment sales (10,772) Net sales $ 1,012,592 For the Quarter Ended June 27, 2020 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings $ 256,016 $ — $ — $ 256,016 Brass rod and forgings — 64,490 — 64,490 OEM components, tube & assemblies 16,812 10,427 32,931 60,170 Valves and plumbing specialties 61,212 — — 61,212 Flex duct and other HVAC components — — 53,176 53,176 Other — 13,702 — 13,702 334,040 88,619 86,107 508,766 Intersegment sales (8,598) Net sales $ 500,168 Disaggregation of revenue from contracts with customers (continued): For the Six Months Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings $ 993,231 $ — $ — $ 993,231 Brass rod and forgings — 274,236 — 274,236 OEM components, tube & assemblies 17,011 23,743 81,516 122,270 Valves and plumbing specialties 249,122 — — 249,122 Flex duct and other HVAC components — — 161,218 161,218 Other — 46,913 — 46,913 1,259,364 344,892 242,734 1,846,990 Intersegment sales (16,250) Net sales $ 1,830,740 For the Six Months Ended June 27, 2020 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings 558,145 — — 558,145 Brass rod and forgings — 164,160 — 164,160 OEM components, tube & assemblies 42,107 21,309 69,504 132,920 Valves and plumbing specialties 118,801 — — 118,801 Flex duct and other HVAC components — — 109,875 109,875 Other — 34,352 — 34,352 719,053 219,821 179,379 1,118,253 Intersegment sales (15,166) Net sales $ 1,103,087

Cash, Cash Equivalents, and Res

Cash, Cash Equivalents, and Restricted Cash	6 Months Ended
	Jun. 26, 2021
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash (In thousands) June 26, December 26, Cash & cash equivalents $ 110,681 $ 119,075 Restricted cash included within other current assets 14,938 8,198 Restricted cash included within other assets 103 103 Total cash, cash equivalents, and restricted cash $ 125,722 $ 127,376 Amounts included in restricted cash relate to required deposits in brokerage accounts that facilitate the Company’s hedging activities as well as imprest funds for the Company’s self-insured workers’ compensation program.

Inventories

Inventories	6 Months Ended
	Jun. 26, 2021
Inventory Disclosure [Abstract]
Inventories	Inventories (In thousands) June 26, December 26, Raw materials and supplies $ 122,931 $ 85,927 Work-in-process 73,336 49,361 Finished goods 197,006 186,785 Valuation reserves (8,291) (7,071) Inventories $ 384,982 $ 315,002

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 26, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	Financial Instruments Derivative Instruments and Hedging Activities The Company’s earnings and cash flows are subject to fluctuations due to changes in commodity prices, foreign currency exchange rates, and interest rates. The Company uses derivative instruments such as commodity futures contracts, foreign currency forward contracts, and interest rate swaps to manage these exposures. All derivatives are recognized in the Condensed Consolidated Balance Sheets at their fair value. On the date the derivative contract is entered into, it is either a) designated as a hedge of a forecasted transaction or the variability of cash flow to be paid (cash flow hedge) or b) not designated in a hedge accounting relationship, even though the derivative contract was executed to mitigate an economic exposure (economic hedge), as the Company does not enter into derivative contracts for trading purposes. Changes in the fair value of a derivative that is qualified, designated, and highly effective as a cash flow hedge are recorded in stockholders’ equity within AOCI, to the extent effective, until they are reclassified to earnings in the same period or periods during which the hedged transaction affects earnings. Changes in the fair value of undesignated derivatives executed as economic hedges are reported in current earnings. The Company documents all relationships between derivative instruments and hedged items, as well as the risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivative instruments that are designated as fair value hedges to specific assets and liabilities in the Condensed Consolidated Balance Sheets and linking cash flow hedges to specific forecasted transactions or variability of cash flow. The Company also assesses, both at the hedge’s inception and on an ongoing basis, whether the designated derivative instruments that are used in hedging transactions are highly effective in offsetting changes in cash flows or fair values of hedged items. When a derivative instrument is determined not to be highly effective as a hedge or the underlying hedged transaction is no longer probable of occurring, hedge accounting is discontinued prospectively in accordance with the derecognition criteria for hedge accounting. Commodity Futures Contracts Copper and brass represent the largest component of the Company’s variable costs of production. The cost of these materials is subject to global market fluctuations caused by factors beyond the Company’s control. The Company occasionally enters into forward fixed-price arrangements with certain customers; the risk of these arrangements is generally managed with commodity futures contracts. These futures contracts have been designated as cash flow hedges. At June 26, 2021, the Company held open futures contracts to purchase approximately $83.9 million of copper over the next 23 months related to fixed price sales orders. The fair value of those futures contracts was a $2.8 million net loss position, which was determined by obtaining quoted market prices (level 1 within the fair value hierarchy). In the next 12 months, the Company will reclassify into earnings realized gains or losses relating to cash flow hedges. At June 26, 2021, this amount was approximately $1.9 million of deferred net losses, net of tax. The Company may also enter into futures contracts to protect the value of inventory against market fluctuations. At June 26, 2021, the Company held open futures contracts to sell approximately $66.7 million of copper over the next nine months related to copper inventory. The fair value of those futures contracts was a $2.6 million net loss position, which was determined by obtaining quoted market prices (level 1 within the fair value hierarchy). The Company presents its derivative assets and liabilities in the Condensed Consolidated Balance Sheets on a net basis by counterparty. The following table summarizes the location and fair value of the derivative instruments and disaggregates the net derivative assets and liabilities into gross components on a contract-by-contract basis: Asset Derivatives Liability Derivatives Fair Value Fair Value (In thousands) Balance Sheet Location June 26, December 26, Balance Sheet Location June 26, December 26, Commodity contracts - gains Other current assets $ 132 $ 1,213 Other current liabilities $ 1,788 $ 68 Commodity contracts - losses Other current assets (83) (8) Other current liabilities (7,285) (5,863) Total derivatives (1) $ 49 $ 1,205 $ (5,497) $ (5,795) (1) Does not include the impact of cash collateral provided to counterparties. The following tables summarize the effects of derivative instruments on the Company’s Condensed Consolidated Statements of Income: For the Quarter Ended For the Six Months Ended (In thousands) Location June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Undesignated derivatives: (Loss) gain on commodity contracts (nonqualifying) Cost of goods sold (1,893) 5,037 (10,423) (4,439) The following tables summarize amounts recognized in and reclassified from AOCI during the period: For the Quarter Ended June 26, 2021 (In thousands) Loss Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) Gain Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ (1,475) Cost of goods sold $ (1,853) Other (9) Other — Total $ (1,484) Total $ (1,853) Amounts recognized in and reclassified from AOCI (continued): For the Quarter Ended June 27, 2020 (In thousands) (Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) Loss Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ (1,715) Cost of goods sold $ 5,075 Other 37 Other 1 Total $ (1,678) Total $ 5,076 For the Six Months Ended June 26, 2021 (In thousands) Gain (Loss) Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) (Gain) Loss Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ 16 Cost of goods sold $ (2,849) Other (12) Other 1 Total $ 4 Total $ (2,848) For the Six Months Ended June 27, 2020 (In thousands) (Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) Loss Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ (5,421) Cost of goods sold $ 5,453 Other 8 Other 1 Total $ (5,413) Total $ 5,454 The Company primarily enters into International Swaps and Derivatives Association master netting agreements with major financial institutions that permit the net settlement of amounts owed under their respective derivative contracts. Under these master netting agreements, net settlement generally permits the Company or the counterparty to determine the net amount payable for contracts due on the same date and in the same currency for similar types of derivative transactions. The master netting agreements generally also provide for net settlement of all outstanding contracts with a counterparty in the case of an event of default or a termination event. The Company does not offset fair value amounts for derivative instruments and fair value amounts recognized for the right to reclaim cash collateral. At June 26, 2021 and December 26, 2020, the Company had recorded restricted cash in other current assets of $14.5 million and $7.6 million, respectively, as collateral related to open derivative contracts under the master netting arrangements. Long-Term Debt The fair value of long-term debt at June 26, 2021 approximates the carrying value on that date. The estimated fair values were determined based on quoted market prices and the current rates offered for debt with similar terms and maturities. The fair value of long-term debt is classified as level 2 within the fair value hierarchy. This classification is defined as a fair value determined using market-based inputs other than quoted prices that are observable for the liability, either directly or indirectly. On March 31, 2021, the Company entered into a Credit Agreement to replace its prior credit agreement that would have matured on December 6, 2021. The Company's total borrowing capacity under the Credit Agreement is $500.0 million. The Credit Agreement provides for an unsecured $400.0 million revolving credit facility, which matures March 31, 2026, and a term loan facility of $100.0 million, which matures March 31, 2022. Funds borrowed under the Credit Agreement may be used by the Company for working capital purposes and other general corporate purposes. In addition, the Credit Agreement provides a sublimit of $50.0 million for the issuance of letters of credit, a sublimit of $35.0 million for loans and letters of credit made in certain foreign currencies, and a Swing Line sublimit of $25.0 million. Outstanding letters of credit and foreign currency loans reduce borrowing availability under the Credit Agreement on a dollar-for-dollar basis. Total borrowings under the Credit Agreement were $350.0 million as of June 26, 2021. During the first quarter of 2021, the Company announced the redemption of its Subordinated Debentures due 2027. The full redemption of outstanding debentures occurred on April 15, 2021 for a total of $291.4 million in principal plus accrued interest and a redemption premium of $5.7 million that was expensed during the second quarter.

Investments in Unconsolidated A

Investments in Unconsolidated Affiliates	6 Months Ended
	Jun. 26, 2021
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Affiliates	Investments in Unconsolidated Affiliates Tecumseh The Company owns a 50 percent interest in an unconsolidated affiliate that acquired Tecumseh Products Company LLC (Tecumseh). The Company also owns a 50 percent interest in a second unconsolidated affiliate that provides financing to Tecumseh. These investments are recorded using the equity method of accounting, as the Company can exercise significant influence but does not own a majority equity interest or otherwise control the respective entities. Under the equity method of accounting, these investments are stated at initial cost and are adjusted for subsequent additional investments and the Company’s proportionate share of earnings or losses and distributions. The Company records its proportionate share of the investees’ net income or loss, net of foreign taxes, one quarter in arrears as income (loss) from unconsolidated affiliates, net of foreign tax, in the Condensed Consolidated Statements of Income and its proportionate share of the investees’ other comprehensive income (loss), net of income taxes, in the Condensed Consolidated Statements of Comprehensive Income and the Condensed Consolidated Statements of Changes in Equity. The U.S. tax effect of the Company’s proportionate share of Tecumseh’s income or loss is recorded in income tax expense in the Condensed Consolidated Statements of Income. In general, the equity investment in unconsolidated affiliates is equal to the current equity investment plus the investees’ net accumulated losses. The following tables present summarized financial information derived from the Company’s equity method investees’ combined consolidated financial statements, which are prepared in accordance with U.S. GAAP. (In thousands) June 26, December 26, Current assets $ 194,383 $ 167,451 Noncurrent assets 73,976 78,241 Current liabilities 145,300 120,202 Noncurrent liabilities 49,770 50,020 For the Quarter Ended For the Six Months Ended (In thousands) June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Net sales $ 103,834 $ 103,550 $ 201,163 $ 210,548 Gross profit 15,323 11,022 25,022 24,508 Net loss (2,038) (17,282) (5,337) (29,967) The Company’s loss from unconsolidated affiliates, net of foreign tax, for the quarter and six months ended June 26, 2021 included net losses of $1.0 million and $2.7 million, respectively, for Tecumseh. The Company’s loss from unconsolidated affiliates, net of foreign tax, for the quarter and six months ended June 27, 2020 included net losses of $8.6 million and $15.0 million, respectively, for Tecumseh. Mueller Middle East On December 30, 2015, the Company entered into a joint venture agreement with Cayan Ventures and Bahrain Mumtalakat Holding Company to build a copper tube mill in Bahrain. The business operates and brands its products under the Mueller Industries family of brands. The Company has invested approximately $5.0 million of cash to date and is the technical and marketing lead with a 40 percent ownership in the joint venture.

Benefit Plans

Benefit Plans	6 Months Ended
	Jun. 26, 2021
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans The Company sponsors several qualified and nonqualified pension plans and other postretirement benefit plans for certain of its employees. The components of net periodic benefit cost (income) are as follows: For the Quarter Ended For the Six Months Ended (In thousands) June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Pension benefits: Interest cost $ 313 $ 866 $ 626 $ 1,724 Expected return on plan assets (904) (1,495) (1,808) (2,990) Amortization of net loss 379 528 757 988 Net periodic benefit income $ (212) $ (101) $ (425) $ (278) Other benefits: Service cost $ 65 $ 56 $ 130 $ 117 Interest cost 87 106 174 215 Amortization of prior service credit (117) (58) (235) (284) Amortization of net gain (33) (47) (64) (100) Curtailment gain — $ (2,591) — $ (2,591) Net periodic benefit cost (income) $ 2 $ (2,534) $ 5 $ (2,643) The components of net periodic benefit cost (income) other than the service cost component are included in other income, net in the Condensed Consolidated Statements of Income.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 26, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company is involved in certain litigation as a result of claims that arose in the ordinary course of business, which management believes will not have a material adverse effect on the Company’s financial position, results of operations, or cash flows. The Company may also realize the benefit of certain legal claims and litigation in the future; these gain contingencies are not recognized in the Condensed Consolidated Financial Statements. Environmental Non-operating Properties Southeast Kansas Sites The Kansas Department of Health and Environment (KDHE) has contacted the Company regarding environmental contamination at three former smelter sites in Kansas (Altoona, East La Harpe, and Lanyon). The Company is not a successor to the companies that operated these smelter sites, but is exploring possible settlement with KDHE and other potentially responsible parties (PRP) in order to avoid litigation. Altoona. Another PRP conducted a site investigation of the Altoona site under a consent decree with KDHE and submitted a removal site evaluation report recommending a remedy. The remedial design plan, which covers both on-site and certain off-site cleanup costs, was approved by the KDHE in 2016. Construction of the remedy was completed in 2018. East La Harpe. At the East La Harpe site, the Company and two other PRPs conducted a site study evaluation under KDHE supervision and prepared a site cleanup plan approved by KDHE. In 2016, the corporate parent (Peabody Energy) of a third party that the Company understands may owe indemnification obligations to one of the other PRPs (Blue Tee) in connection with the East La Harpe site filed for protection under Chapter 11 of the U.S. Bankruptcy Code. KDHE has extended the deadline for the PRPs to develop a repository design plan to allow for wetlands permitting to take place. In December 2018, KDHE provided a draft agreement which contemplates the use of funds KDHE obtained from two other parties (Peabody Energy and Blue Tee) to fund part of the remediation, and removes Blue Tee from the PRPs’ agreement with KDHE. The Company is currently negotiating the terms of that draft agreement. Lanyon. With respect to the Lanyon Site, in 2016, the Company received a general notice letter from the United States Environmental Protection Agency (EPA) asserting that the Company is a PRP, which the Company has denied. EPA issued an interim record of decision in 2017 and has been remediating properties at the site. The Company’s reserve for its proportionate share of the remediation costs associated with these three Southeast Kansas sites is $5.6 million. Shasta Area Mine Sites Mining Remedial Recovery Company (MRRC), a wholly owned subsidiary, owns certain inactive mines in Shasta County, California. MRRC has continued a program, begun in the late 1980s, of implementing various remedial measures, including sealing mine portals with concrete plugs in portals that were discharging water. The sealing program achieved significant reductions in the metal load in discharges from these adits; however, additional reductions are required pursuant to an order issued by the California Regional Water Quality Control Board (QCB). In response to a 1996 QCB Order, MRRC completed a feasibility study in 1997 describing measures designed to mitigate the effects of acid rock drainage. In December 1998, the QCB modified the 1996 order extending MRRC’s time to comply with water quality standards. In September 2002, the QCB adopted a new order requiring MRRC to adopt Best Management Practices (BMP) to control discharges of acid mine drainage, and again extended the time to comply with water quality standards until September 2007. During that time, implementation of BMP further reduced impacts of acid rock drainage; however, full compliance has not been achieved. The QCB is presently renewing MRRC’s discharge permit and will concurrently issue a new order. It is expected that the new 10-year permit will include an order requiring continued implementation of BMP through 2030 to address residual discharges of acid rock drainage. The Company currently estimates that it will spend between approximately $13.9 million and $18.0 million for remediation at these sites over the next 30 years and has accrued a reserve at the low end of this range. Lead Refinery Site U.S.S. Lead Refinery, Inc. (Lead Refinery), a non-operating wholly owned subsidiary of MRRC, has conducted corrective action and interim remedial activities (collectively, Site Activities) at Lead Refinery’s East Chicago, Indiana site pursuant to the Resource Conservation and Recovery Act since December 1996. Although the Site Activities have been substantially concluded, Lead Refinery is required to perform monitoring and maintenance-related activities pursuant to a post-closure permit issued by the Indiana Department of Environmental Management effective as of March 2, 2013. Approximate costs to comply with the post-closure permit, including associated general and administrative costs, are estimated at between $1.7 million and $2.4 million over the next 16 years. The Company has recorded a reserve at the low end of this range. On April 9, 2009, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the U.S. Environmental Protection Agency (EPA) added the Lead Refinery site and surrounding properties to the National Priorities List (NPL). On July 17, 2009, Lead Refinery received a written notice from the EPA indicating that it may be a PRP under CERCLA due to the release or threat of release of hazardous substances including lead into properties surrounding the Lead Refinery NPL site. The EPA identified two other PRPs in connection with that matter. In November 2012, the EPA adopted a remedy for the surrounding properties and in September 2014, the EPA announced that it had entered into a settlement with the two other PRPs whereby they will pay approximately $26.0 million to fund the cleanup of approximately 300 properties surrounding the Lead Refinery NPL site (zones 1 and 3 of operable unit 1) and perform certain remedial action tasks. On November 8, 2016, the Company, its subsidiary Arava Natural Resources Company, Inc. (Arava), and Arava’s subsidiary MRRC each received general notice letters from the EPA asserting that they may be PRPs in connection with the Lead Refinery NPL site. The Company, Arava, and MRRC have denied liability for any remedial action and response costs associated with the Lead Refinery NPL site. In June 2017, the EPA requested that Lead Refinery conduct, and the Company fund, a remedial investigation and feasibility study of operable unit 2 of the Lead Refinery NPL site pursuant to a proposed administrative settlement agreement and order on consent. The Company and Lead Refinery entered into that agreement in September 2017. The Company has made a capital contribution to Lead Refinery to conduct the remedial investigation and feasibility study with respect to operable unit 2 and has provided financial assurance in the amount of $1.0 million. The remedial investigation and feasibility study remain ongoing. The EPA has also asserted its position that Mueller is a responsible party for the Lead Refinery NPL site, and accordingly is responsible for a share of remedial action and response costs at the site and in the adjacent residential area. In January 2018, the EPA issued two unilateral administrative orders (UAOs) directing the Company, Lead Refinery, and four other PRPs to conduct soil and interior remediation of certain residences at the Lead Refinery NPL site (zones 2 and 3 of operable unit 1). The Company and Lead Refinery have reached agreement with the four other PRPs to implement these two UAOs, with the Company agreeing to pay, on an interim basis, (i) an estimated $4.5 million (subject to potential change through a future reallocation process) of the approximately $25.0 million the PRPs currently estimate it will cost to implement the UAOs, which estimate is subject to change, and (ii) $2.0 million relating to past costs incurred by other PRPs for work conducted at the site, as well as the possibility of up to $0.7 million in further payments for ongoing work by those PRPs. As of June 26, 2021, the Company has made payments of approximately $7.6 million related to the aforementioned agreement with the other PRPs. The Company disputes that it was properly named in the UAOs, and has reserved its rights to petition the EPA for reimbursement of any costs incurred to comply with the UAOs upon the completion of the work required therein. In October 2017 and March 2018, separate groups of private plaintiffs sued the Company, Arava, MRRC, and Lead Refinery, along with other defendants, in two civil tort actions relating to the site. The Company, Arava, and MRRC have been voluntarily dismissed from both litigations without prejudice, but Lead Refinery remains a party to each. At this juncture, the Company is unable to determine the likelihood of a material adverse outcome or the amount or range of a potential loss in excess of the current reserve with respect to any remedial action or litigation relating to the Lead Refinery NPL site, either at Lead Refinery’s former operating site (operable unit 2) or the adjacent residential area (operable unit 1), including, but not limited to, EPA oversight costs for which EPA may attempt to seek reimbursement from the Company, and past costs for which other PRPs may attempt to seek contribution from the Company. Bonita Peak Mining District Following an August 2015 spill from the Gold King Mine into the Animas River near Silverton, Colorado, the EPA listed the Bonita Peak Mining District on the NPL. Said listing was finalized in September 2016. The Bonita Peak Mining District encompasses 48 mining sites within the Animas River watershed, including the Sunnyside Mine, the American Tunnel, and the Sunbank Group. On or about July 25, 2017, Washington Mining Company (Washington Mining) (a wholly-owned subsidiary of the Company’s wholly-owned subsidiary, Arava), received a general notice letter from the EPA stating that Washington Mining may be a PRP under CERCLA in connection with the Bonita Peak Mining District site and therefore responsible for the remediation of certain portions of the site, along with related costs incurred by the EPA. Shortly thereafter, the Company received a substantively identical letter asserting that it may be a PRP at the site and similarly responsible for the cleanup of certain portions of the site. The general notice letters identify one other PRP at the site, and do not require specific action by Washington Mining or the Company at this time. At this juncture, the Company is unable to determine the likelihood of a materially adverse outcome or the amount or range of a potential loss with respect to any remedial action related to the Bonita Peak Mining District NPL site. Operating Properties Mueller Copper Tube Products, Inc. In 1999, Mueller Copper Tube Products, Inc. (MCTP), a wholly owned subsidiary, commenced a cleanup and remediation of soil and groundwater at its Wynne, Arkansas plant to remove trichloroethylene, a cleaning solvent formerly used by MCTP. On August 30, 2000, MCTP received approval of its Final Comprehensive Investigation Report and Storm Water Drainage Investigation Report addressing the treatment of soils and groundwater from the Arkansas Department of Environmental Quality (ADEQ). The Company established a reserve for this project in connection with the acquisition of MCTP in 1998. Effective November 17, 2008, MCTP entered into a Settlement Agreement and Administrative Order by Consent to submit a Supplemental Investigation Work Plan (SIWP) and subsequent Final Remediation Work Plan (RWP) for the site. By letter dated January 20, 2010, ADEQ approved the SIWP as submitted, with changes acceptable to the Company. On December 16, 2011, MCTP entered into an amended Administrative Order by Consent to prepare and implement a revised RWP regarding final remediation for the Site. The remediation system was activated in February 2014. Costs to implement the work plans, including associated general and administrative costs, are estimated to approximate $0.9 million to $1.1 million over the next five years. The Company has recorded a reserve at the low end of this range. United States Department of Commerce Antidumping Review On December 24, 2008, the Department of Commerce (DOC) initiated an antidumping administrative review of the antidumping duty order covering circular welded non-alloy steel pipe and tube from Mexico for the November 1, 2007 through October 31, 2008 period of review. The DOC selected Mueller Comercial as a respondent in the review. On April 19, 2010, the DOC published the final results of the review and assigned Mueller Comercial an antidumping duty rate of 48.33 percent. On May 25, 2010, the Company appealed the final results to the U.S. Court of International Trade (CIT). On December 16, 2011, the CIT issued a decision remanding the Department’s final results. While the matter was still pending, the Company and the United States reached an agreement to settle the appeal. Subject to the conditions of the agreement, the Company anticipated that certain of its subsidiaries would incur antidumping duties on subject imports made during the period of review and, as such, established a reserve for this matter. After the lapse of the statutory period of time during which U.S. Customs and Border Protection (CBP) was required, but failed, to liquidate the entries at the settled rate, the Company released the reserve. Between October 30, 2015 and November 27, 2015, CBP sent a series of invoices to Southland Pipe Nipples Co., Inc. (Southland), requesting payment of approximately $3.0 million in duties and interest in connection with 795 import entries made during the November 1, 2007 through October 31, 2008 period. On January 26, 2016 and January 27, 2016, Southland filed protests with CBP in connection with these invoices, noting that CBP’s asserted claims were not made in accordance with applicable law, including statutory provisions governing deemed liquidation. The Company believes in the merits of the legal objections raised in Southland’s protests, and CBP’s response to Southland’s protests is currently pending. Given the procedural posture and issues raised by this legal dispute, the Company cannot estimate the amount of potential duty liability, if any, that may result from CBP’s asserted claims. Deepwater Horizon Economic and Property Damage Claim During 2020, Mueller Copper Tube Company, a wholly owned subsidiary of the Company, collected approximately $22.1 million related to its claim under the Deepwater Horizon Economic and Property Damage Settlement Program. The collected amount represents settlement proceeds received after the payment of fees and expenses. Guarantees Guarantees, in the form of letters of credit, are issued by the Company generally to assure the payment of insurance deductibles, certain retiree health benefits, and debt at certain unconsolidated affiliates. The terms of the guarantees are generally one year but are renewable annually as required. These letters are primarily backed by the Company’s revolving credit facility. The maximum payments that the Company could be required to make under its guarantees at June 26, 2021 were $23.9 million.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 26, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s effective tax rate for the second quarter of 2021 was 26 percent compared with 26 percent for the same period last year. The primary items impacting the effective tax rate for the second quarter of 2021 were the provision for state income taxes, net of the federal benefit, of $5.3 million and foreign tax rates higher than statutory tax rates of $1.8 million. The items impacting the effective tax rate for the second quarter of 2020 were primarily attributable to the provision for state income taxes, net of the federal benefit, of $1.2 million and other items of $1.3 million. The Company’s effective tax rate for the first half of 2021 was 25 percent compared with 26 percent for the same period last year. The items impacting the effective tax rate for the first half of 2021 primarily related to the provision for state income taxes, net of the federal benefit, of $7.7 million and the effect of foreign tax rates higher than statutory tax rates of $3.1 million. The items impacting the effective tax rate for the first half of 2020 were primarily related to the provision for state income taxes, net of the federal benefit, of $3.3 million and foreign tax rates higher than statutory tax rates of $1.5 million. The Company files a consolidated U.S. federal income tax return and numerous consolidated and separate-company income tax returns in many state, local, and foreign jurisdictions. The statute of limitations is open for the Company’s federal tax return for 2015 and 2017 and all subsequent years. The statutes of limitations for most state returns are open for 2017 and all subsequent years, and some state and foreign returns are also open for some earlier tax years due to differing statute periods. The Internal Revenue Service is auditing the Company’s 2015 and 2017 federal consolidated returns. While the Company believes that it is

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 26, 2021
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) AOCI includes certain foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency, net deferred gains and losses on certain derivative instruments accounted for as cash flow hedges, adjustments to pension and OPEB liabilities, and other comprehensive income attributable to unconsolidated affiliates. The following tables provide changes in AOCI by component, net of taxes and noncontrolling interests (amounts in parentheses indicate debits to AOCI): For the Six Months Ended June 26, 2021 (In thousands) Cumulative Translation Adjustment Unrealized Gain (Loss) on Derivatives Pension/OPEB Liability Adjustment Attributable to Unconsol. Affiliates Total Balance as of December 26, 2020 $ (37,339) $ 984 $ (17,203) $ (1,325) $ (54,883) Other comprehensive income (loss) before reclassifications 8,248 4 (400) 1,234 9,086 Amounts reclassified from AOCI — (2,848) 383 — (2,465) Net current-period other comprehensive income (loss) 8,248 (2,844) (17) 1,234 6,621 Balance as of June 26, 2021 $ (29,091) $ (1,860) $ (17,220) $ (91) $ (48,262) For the Six Months Ended June 27, 2020 (In thousands) Cumulative Translation Adjustment Unrealized Gain (Loss) on Derivatives Pension/OPEB Liability Adjustment Attributable to Unconsol. Affiliates Total Balance as of December 28, 2019 $ (46,198) $ 476 $ (21,855) $ (1,193) $ (68,770) Other comprehensive loss before reclassifications (19,622) (5,413) (1,034) (903) (26,972) Amounts reclassified from AOCI — 5,454 489 — 5,943 Net current-period other comprehensive (loss) income (19,622) 41 (545) (903) (21,029) Balance as of June 27, 2020 $ (65,820) $ 517 $ (22,400) $ (2,096) $ (89,799) Reclassification adjustments out of AOCI were as follows: Amount reclassified from AOCI For the Quarter Ended For the Six Months Ended (In thousands) June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Affected line item Unrealized (gains) losses on derivative commodity contracts $ (2,390) $ 6,361 $ (3,689) $ 6,829 Cost of goods sold 537 (1,285) 841 (1,375) Income tax expense (benefit) $ (1,853) $ 5,076 $ (2,848) $ 5,454 Net of tax and noncontrolling interests Amortization of net loss and prior service cost on employee benefit plans $ 229 $ 423 $ 458 $ 604 Other income, net (38) (86) (75) (115) Income tax benefit $ 191 $ 337 $ 383 $ 489 Net of tax and noncontrolling interests

Recent Accounting Standards (Po

Recent Accounting Standards (Policies)	6 Months Ended
	Jun. 26, 2021
Accounting Changes and Error Corrections [Abstract]
Recently Adopted and Issued Accounting Standards	Adopted In October 2020, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2020-10, Codification Improvements: An Amendment of the FASB Accounting Standards Codification . The ASU facilitates updates to the Accounting Standards Codification for technical corrections such as conforming amendments, clarifications to guidance, simplifications to wording or structure of guidance, and other minor improvements. The Company adopted the ASU during the first quarter of 2021 using a retrospective approach. The adoption of the ASU did not have a material impact on the Company’s Condensed Consolidated Financial Statements. In January 2020, the FASB issued ASU No. 2020-01, Investments - Equity Securities (Topic 321), Investments - Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815): Clarifying the Interactions between Topic 321, Topic 323, and Topic 815 . The new guidance addresses accounting for the transition into and out of the equity method and measuring certain purchased options and forward contracts to acquire investments. The Company adopted the ASU during the first quarter of 2021 using a prospective approach. The adoption of the ASU did not have a material impact on the Company’s Condensed Consolidated Financial Statements. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes . The new guidance affects general principles within Topic 740, Income Taxes. The amendments of ASU 2019-12 are meant to simplify and reduce the cost of accounting for income taxes. The Company adopted the ASU during the first quarter of 2021 using a prospective approach. The adoption of the ASU did not have a material impact on the Company’s Condensed Consolidated Financial Statements. Issued In January 2021, the FASB issued ASU No. 2021-01, Reference Rate Reform (Topic 848): An Amendment of the FASB Accounting Standards Codification. The new guidance was issued in response to concerns about structural risks of interbank offered rates, and, particularly, the risk of cessation of the London Interbank Offered Rate (LIBOR). Regulators in numerous jurisdictions around the world have undertaken reference rate reform initiatives to identify alternative reference rates that are more observable or transaction based and less susceptible to manipulation. The ASU is effective in 2021 but can be applied through December 31, 2022. The updated guidance requires retrospective adoption, and early adoption is permitted. The Company does not expect the adoption of the ASU to have a material impact on its Condensed Consolidated Financial Statements.

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 26, 2021
Segment Reporting [Abstract]
Summary of Segment Information	Summarized segment information is as follows: For the Quarter Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 711,616 $ 180,040 $ 131,708 $ (10,772) $ 1,012,592 Cost of goods sold 558,278 155,399 96,303 (10,268) 799,712 Depreciation and amortization 5,515 1,694 2,753 1,172 11,134 Selling, general, and administrative expense 23,315 2,448 7,280 10,889 43,932 Operating income 124,508 20,499 25,372 (12,565) 157,814 Interest expense (1,866) Redemption premium (5,674) Other income, net 683 Income before income taxes $ 150,957 Segment information (continued): For the Quarter Ended June 27, 2020 (In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 334,040 $ 88,619 $ 86,107 $ (8,598) $ 500,168 Cost of goods sold 272,271 75,274 64,540 (8,926) 403,159 Depreciation and amortization 5,456 1,995 2,757 889 11,097 Selling, general, and administrative expense 15,239 2,477 6,457 9,443 33,616 Operating income 41,074 8,873 12,353 (10,004) 52,296 Interest expense (4,973) Other income, net 2,834 Income before income taxes $ 50,157 For the Six Months Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 1,259,364 $ 344,892 $ 242,734 $ (16,250) $ 1,830,740 Cost of goods sold 1,008,632 296,290 180,385 (17,177) 1,468,130 Depreciation and amortization 11,725 3,437 5,382 2,345 22,889 Selling, general, and administrative expense 47,401 5,819 14,260 21,887 89,367 Operating income 191,606 39,346 42,707 (23,305) 250,354 Interest expense (6,335) Redemption premium (5,674) Other income, net 1,260 Income before income taxes $ 239,605 Segment information (continued): For the Six Months Ended June 27, 2020 ( In thousands) Piping Systems Industrial Metals Climate Corporate and Eliminations Total Net sales $ 719,053 $ 219,821 $ 179,379 $ (15,166) $ 1,103,087 Cost of goods sold 591,435 190,071 135,633 (5,265) 911,874 Depreciation and amortization 11,155 3,997 5,223 1,761 22,136 Selling, general, and administrative expense 35,678 5,698 13,156 21,836 76,368 Asset impairments 3,035 — — — 3,035 Litigation settlement, net — — — (21,933) (21,933) Operating income 77,750 20,055 25,367 (11,565) 111,607 Interest expense (10,352) Other income, net 3,112 Income before income taxes $ 104,367 The following table presents total assets attributable to each segment: (In thousands) June 26, 2021 December 26, 2020 Segment assets: Piping Systems $ 1,222,336 $ 977,937 Industrial Metals 173,227 152,683 Climate 272,318 258,668 General Corporate 121,556 139,280 $ 1,789,437 $ 1,528,568
Disaggregation of Revenue From Contracts with Customers	The following tables represent a disaggregation of revenue from contracts with customers, along with the reportable segment for each category: For the Quarter Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings $ 567,092 $ — $ — $ 567,092 Brass rod and forgings — 142,974 — 142,974 OEM components, tube & assemblies 8,456 12,710 43,449 64,615 Valves and plumbing specialties 136,068 — — 136,068 Flex duct and other HVAC components — — 88,259 88,259 Other — 24,356 — 24,356 711,616 180,040 131,708 1,023,364 Intersegment sales (10,772) Net sales $ 1,012,592 For the Quarter Ended June 27, 2020 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings $ 256,016 $ — $ — $ 256,016 Brass rod and forgings — 64,490 — 64,490 OEM components, tube & assemblies 16,812 10,427 32,931 60,170 Valves and plumbing specialties 61,212 — — 61,212 Flex duct and other HVAC components — — 53,176 53,176 Other — 13,702 — 13,702 334,040 88,619 86,107 508,766 Intersegment sales (8,598) Net sales $ 500,168 Disaggregation of revenue from contracts with customers (continued): For the Six Months Ended June 26, 2021 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings $ 993,231 $ — $ — $ 993,231 Brass rod and forgings — 274,236 — 274,236 OEM components, tube & assemblies 17,011 23,743 81,516 122,270 Valves and plumbing specialties 249,122 — — 249,122 Flex duct and other HVAC components — — 161,218 161,218 Other — 46,913 — 46,913 1,259,364 344,892 242,734 1,846,990 Intersegment sales (16,250) Net sales $ 1,830,740 For the Six Months Ended June 27, 2020 (In thousands) Piping Systems Industrial Metals Climate Total Tube and fittings 558,145 — — 558,145 Brass rod and forgings — 164,160 — 164,160 OEM components, tube & assemblies 42,107 21,309 69,504 132,920 Valves and plumbing specialties 118,801 — — 118,801 Flex duct and other HVAC components — — 109,875 109,875 Other — 34,352 — 34,352 719,053 219,821 179,379 1,118,253 Intersegment sales (15,166) Net sales $ 1,103,087

Cash, Cash Equivalents, and R_2

Cash, Cash Equivalents, and Restricted Cash (Tables)	6 Months Ended
	Jun. 26, 2021
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	(In thousands) June 26, December 26, Cash & cash equivalents $ 110,681 $ 119,075 Restricted cash included within other current assets 14,938 8,198 Restricted cash included within other assets 103 103 Total cash, cash equivalents, and restricted cash $ 125,722 $ 127,376
Restrictions on Cash and Cash Equivalents	(In thousands) June 26, December 26, Cash & cash equivalents $ 110,681 $ 119,075 Restricted cash included within other current assets 14,938 8,198 Restricted cash included within other assets 103 103 Total cash, cash equivalents, and restricted cash $ 125,722 $ 127,376

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 26, 2021
Inventory Disclosure [Abstract]
Inventories	(In thousands) June 26, December 26, Raw materials and supplies $ 122,931 $ 85,927 Work-in-process 73,336 49,361 Finished goods 197,006 186,785 Valuation reserves (8,291) (7,071) Inventories $ 384,982 $ 315,002

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Jun. 26, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments Designated as Cash Flow Hedges Reflected in the Financial Statements	The following table summarizes the location and fair value of the derivative instruments and disaggregates the net derivative assets and liabilities into gross components on a contract-by-contract basis: Asset Derivatives Liability Derivatives Fair Value Fair Value (In thousands) Balance Sheet Location June 26, December 26, Balance Sheet Location June 26, December 26, Commodity contracts - gains Other current assets $ 132 $ 1,213 Other current liabilities $ 1,788 $ 68 Commodity contracts - losses Other current assets (83) (8) Other current liabilities (7,285) (5,863) Total derivatives (1) $ 49 $ 1,205 $ (5,497) $ (5,795) (1) Does not include the impact of cash collateral provided to counterparties.
Schedule of Fair Value Hedges	The following tables summarize the effects of derivative instruments on the Company’s Condensed Consolidated Statements of Income: For the Quarter Ended For the Six Months Ended (In thousands) Location June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Undesignated derivatives: (Loss) gain on commodity contracts (nonqualifying) Cost of goods sold (1,893) 5,037 (10,423) (4,439)
Summary of Activities Related to Derivative Instruments Classified as Cash Flow Hedges	The following tables summarize amounts recognized in and reclassified from AOCI during the period: For the Quarter Ended June 26, 2021 (In thousands) Loss Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) Gain Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ (1,475) Cost of goods sold $ (1,853) Other (9) Other — Total $ (1,484) Total $ (1,853) Amounts recognized in and reclassified from AOCI (continued): For the Quarter Ended June 27, 2020 (In thousands) (Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) Loss Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ (1,715) Cost of goods sold $ 5,075 Other 37 Other 1 Total $ (1,678) Total $ 5,076 For the Six Months Ended June 26, 2021 (In thousands) Gain (Loss) Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) (Gain) Loss Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ 16 Cost of goods sold $ (2,849) Other (12) Other 1 Total $ 4 Total $ (2,848) For the Six Months Ended June 27, 2020 (In thousands) (Loss) Gain Recognized in AOCI (Effective Portion), Net of Tax Classification Gains (Losses) Loss Reclassified from AOCI (Effective Portion), Net of Tax Cash flow hedges: Commodity contracts $ (5,421) Cost of goods sold $ 5,453 Other 8 Other 1 Total $ (5,413) Total $ 5,454

Investments in Unconsolidated_2

Investments in Unconsolidated Affiliates (Tables)	6 Months Ended
	Jun. 26, 2021
Equity Method Investments and Joint Ventures [Abstract]
Summarized Financial Information Derived From the Company's Equity Method Investee's Consolidated Financial Statements	The following tables present summarized financial information derived from the Company’s equity method investees’ combined consolidated financial statements, which are prepared in accordance with U.S. GAAP. (In thousands) June 26, December 26, Current assets $ 194,383 $ 167,451 Noncurrent assets 73,976 78,241 Current liabilities 145,300 120,202 Noncurrent liabilities 49,770 50,020 For the Quarter Ended For the Six Months Ended (In thousands) June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Net sales $ 103,834 $ 103,550 $ 201,163 $ 210,548 Gross profit 15,323 11,022 25,022 24,508 Net loss (2,038) (17,282) (5,337) (29,967)

Benefit Plans (Tables)

Benefit Plans (Tables)	6 Months Ended
	Jun. 26, 2021
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost (Income)	The components of net periodic benefit cost (income) are as follows: For the Quarter Ended For the Six Months Ended (In thousands) June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Pension benefits: Interest cost $ 313 $ 866 $ 626 $ 1,724 Expected return on plan assets (904) (1,495) (1,808) (2,990) Amortization of net loss 379 528 757 988 Net periodic benefit income $ (212) $ (101) $ (425) $ (278) Other benefits: Service cost $ 65 $ 56 $ 130 $ 117 Interest cost 87 106 174 215 Amortization of prior service credit (117) (58) (235) (284) Amortization of net gain (33) (47) (64) (100) Curtailment gain — $ (2,591) — $ (2,591) Net periodic benefit cost (income) $ 2 $ (2,534) $ 5 $ (2,643)

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 26, 2021
Equity [Abstract]
Changes in AOCI by Component, Net of Taxes and Noncontrolling Interest	The following tables provide changes in AOCI by component, net of taxes and noncontrolling interests (amounts in parentheses indicate debits to AOCI): For the Six Months Ended June 26, 2021 (In thousands) Cumulative Translation Adjustment Unrealized Gain (Loss) on Derivatives Pension/OPEB Liability Adjustment Attributable to Unconsol. Affiliates Total Balance as of December 26, 2020 $ (37,339) $ 984 $ (17,203) $ (1,325) $ (54,883) Other comprehensive income (loss) before reclassifications 8,248 4 (400) 1,234 9,086 Amounts reclassified from AOCI — (2,848) 383 — (2,465) Net current-period other comprehensive income (loss) 8,248 (2,844) (17) 1,234 6,621 Balance as of June 26, 2021 $ (29,091) $ (1,860) $ (17,220) $ (91) $ (48,262) For the Six Months Ended June 27, 2020 (In thousands) Cumulative Translation Adjustment Unrealized Gain (Loss) on Derivatives Pension/OPEB Liability Adjustment Attributable to Unconsol. Affiliates Total Balance as of December 28, 2019 $ (46,198) $ 476 $ (21,855) $ (1,193) $ (68,770) Other comprehensive loss before reclassifications (19,622) (5,413) (1,034) (903) (26,972) Amounts reclassified from AOCI — 5,454 489 — 5,943 Net current-period other comprehensive (loss) income (19,622) 41 (545) (903) (21,029) Balance as of June 27, 2020 $ (65,820) $ 517 $ (22,400) $ (2,096) $ (89,799)
Reclassification Adjustments Out of AOCI	Reclassification adjustments out of AOCI were as follows: Amount reclassified from AOCI For the Quarter Ended For the Six Months Ended (In thousands) June 26, 2021 June 27, 2020 June 26, 2021 June 27, 2020 Affected line item Unrealized (gains) losses on derivative commodity contracts $ (2,390) $ 6,361 $ (3,689) $ 6,829 Cost of goods sold 537 (1,285) 841 (1,375) Income tax expense (benefit) $ (1,853) $ 5,076 $ (2,848) $ 5,454 Net of tax and noncontrolling interests Amortization of net loss and prior service cost on employee benefit plans $ 229 $ 423 $ 458 $ 604 Other income, net (38) (86) (75) (115) Income tax benefit $ 191 $ 337 $ 383 $ 489 Net of tax and noncontrolling interests

Earnings per Common Share (Deta

Earnings per Common Share (Details) - shares shares in Thousands	3 Months Ended
	Jun. 26, 2021	Jun. 27, 2020
Earnings Per Share [Abstract]
Stock-based awards excluded from computation of diluted earnings per share (in shares)	5	8

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Millions	Jan. 29, 2021	Aug. 03, 2020	Jan. 17, 2020	Jun. 26, 2021	Mar. 27, 2021
Hart & Cooley Flexible Duct Business [Member]
Business Acquisition [Line Items]
Consideration transferred net of working capital adjustments	$ 15.4
Cash portion of acquisition price	14
Payment for contingent consideration	1.4
Fair value of assets acquired	15.3
Fair value of property, plant and equipment acquired	10.8
Fair value of inventories acquired	4.5
Tax-deductible goodwill	$ 0.1
Increase (decrease) in property plant and equipment				$ 2.4
Increase (decrease) in goodwill				1
Recognition of contingent consideration				1.4
Wieland-Kessler LLC [Member]
Business Acquisition [Line Items]
Consideration transferred net of working capital adjustments		$ 57.2
Fair value of assets acquired		27.3
Tax-deductible goodwill		$ 29.9
Increase (decrease) in property plant and equipment				(1.4)
Increase (decrease) in goodwill				$ 1.4	$ (1.5)
Increase in intangible assets					$ 1.5
Shoals Tubular, Inc. [Member]
Business Acquisition [Line Items]
Consideration transferred net of working capital adjustments			$ 15.3
Cash portion of acquisition price			15.3
Fair value of assets acquired			6.2
Fair value of property, plant and equipment acquired			3.7
Fair value of inventories acquired			1.8
Tax-deductible goodwill			9.3
Fair value of accounts receivable acquired			0.7
Fair value of liabilities acquired			$ 0.2

Segment Information - Summary o

Segment Information - Summary of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020	Dec. 26, 2020
Summary of segment information [Abstract]
Net sales	$ 1,012,592	$ 500,168	$ 1,830,740	$ 1,103,087
Cost of goods sold	799,712	403,159	1,468,130	911,874
Depreciation and amortization	11,134	11,097	22,889	22,136
Selling, general, and administrative expense	43,932	33,616	89,367	76,368
Asset impairments	0	0	0	3,035
Litigation settlement, net	0	0	0	(21,933)
Operating income	157,814	52,296	250,354	111,607
Interest expense	(1,866)	(4,973)	(6,335)	(10,352)
Redemption premium	(5,674)	0	(5,674)	0
Other income (expense), net	683	2,834	1,260	3,112
Income before income taxes	150,957	50,157	239,605	104,367
Assets	1,789,437		1,789,437		$ 1,528,568
Operating Segments [Member]
Summary of segment information [Abstract]
Net sales	1,023,364	508,766	1,846,990	1,118,253
Operating Segments [Member] | Piping Systems [Member]
Summary of segment information [Abstract]
Net sales	711,616	334,040	1,259,364	719,053
Cost of goods sold	558,278	272,271	1,008,632	591,435
Depreciation and amortization	5,515	5,456	11,725	11,155
Selling, general, and administrative expense	23,315	15,239	47,401	35,678
Asset impairments				3,035
Litigation settlement, net				0
Operating income	124,508	41,074	191,606	77,750
Assets	1,222,336		1,222,336		977,937
Operating Segments [Member] | Industrial Metals [Member]
Summary of segment information [Abstract]
Net sales	180,040	88,619	344,892	219,821
Cost of goods sold	155,399	75,274	296,290	190,071
Depreciation and amortization	1,694	1,995	3,437	3,997
Selling, general, and administrative expense	2,448	2,477	5,819	5,698
Asset impairments				0
Litigation settlement, net				0
Operating income	20,499	8,873	39,346	20,055
Assets	173,227		173,227		152,683
Operating Segments [Member] | Climate [Member]
Summary of segment information [Abstract]
Net sales	131,708	86,107	242,734	179,379
Cost of goods sold	96,303	64,540	180,385	135,633
Depreciation and amortization	2,753	2,757	5,382	5,223
Selling, general, and administrative expense	7,280	6,457	14,260	13,156
Asset impairments				0
Litigation settlement, net				0
Operating income	25,372	12,353	42,707	25,367
Assets	272,318		272,318		258,668
Corporate and Eliminations [Member]
Summary of segment information [Abstract]
Net sales	(10,772)	(8,598)	(16,250)	(15,166)
Cost of goods sold	(10,268)	(8,926)	(17,177)	(5,265)
Depreciation and amortization	1,172	889	2,345	1,761
Selling, general, and administrative expense	10,889	9,443	21,887	21,836
Asset impairments				0
Litigation settlement, net				(21,933)
Operating income	(12,565)	$ (10,004)	(23,305)	$ (11,565)
Assets	$ 121,556		$ 121,556		$ 139,280

Segment Information - Net Sales

Segment Information - Net Sales by Major Product Line (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,012,592	$ 500,168	$ 1,830,740	$ 1,103,087
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	1,023,364	508,766	1,846,990	1,118,253
Operating Segments [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	711,616	334,040	1,259,364	719,053
Operating Segments [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	180,040	88,619	344,892	219,821
Operating Segments [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	131,708	86,107	242,734	179,379
Operating Segments [Member] | Tube and fittings [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	567,092	256,016	993,231	558,145
Operating Segments [Member] | Tube and fittings [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	567,092	256,016	993,231	558,145
Operating Segments [Member] | Tube and fittings [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Tube and fittings [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Brass rod and forgings [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	142,974	64,490	274,236	164,160
Operating Segments [Member] | Brass rod and forgings [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Brass rod and forgings [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	142,974	64,490	274,236	164,160
Operating Segments [Member] | Brass rod and forgings [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | OEM components, tube and assemblies [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	64,615	60,170	122,270	132,920
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	8,456	16,812	17,011	42,107
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	12,710	10,427	23,743	21,309
Operating Segments [Member] | OEM components, tube and assemblies [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	43,449	32,931	81,516	69,504
Operating Segments [Member] | Valves and plumbing specialties [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	136,068	61,212	249,122	118,801
Operating Segments [Member] | Valves and plumbing specialties [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	136,068	61,212	249,122	118,801
Operating Segments [Member] | Valves and plumbing specialties [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Valves and plumbing specialties [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Flex Duct and Other HVAC Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	88,259	53,176	161,218	109,875
Operating Segments [Member] | Flex Duct and Other HVAC Components [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Flex Duct and Other HVAC Components [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Flex Duct and Other HVAC Components [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	88,259	53,176	161,218	109,875
Operating Segments [Member] | Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	24,356	13,702	46,913	34,352
Operating Segments [Member] | Other [Member] | Piping Systems [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Operating Segments [Member] | Other [Member] | Industrial Metals [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	24,356	13,702	46,913	34,352
Operating Segments [Member] | Other [Member] | Climate [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	0	0	0	0
Intersegment Sales [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ (10,772)	$ (8,598)	$ (16,250)	$ (15,166)

Cash, Cash Equivalents, and R_3

Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020	Jun. 27, 2020	Dec. 28, 2019
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 110,681	$ 119,075
Restricted cash included within other current assets	14,938	8,198
Restricted cash included within other assets	103	103
Total cash, cash equivalents, and restricted cash	$ 125,722	$ 127,376	$ 124,512	$ 98,042

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 122,931	$ 85,927
Work-in-process	73,336	49,361
Finished goods	197,006	186,785
Valuation reserves	(8,291)	(7,071)
Inventories	$ 384,982	$ 315,002

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($)	Apr. 15, 2021	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020	Mar. 31, 2021	Dec. 26, 2020
Derivative [Line Items]
Restricted cash in other current assets as collateral related to open derivative contracts		$ 14,500,000		$ 14,500,000			$ 7,600,000
Redemption premium		(5,674,000)	$ 0	(5,674,000)	$ 0
Line of Credit
Derivative [Line Items]
Maximum borrowing capacity						$ 500,000,000
Total borrowing capacity		350,000,000		350,000,000
Line of Credit | Revolving Credit Facility
Derivative [Line Items]
Maximum borrowing capacity						400,000,000
Line of Credit | Term Loan Facility
Derivative [Line Items]
Maximum borrowing capacity						100,000,000
Line of Credit | Letter of Credit
Derivative [Line Items]
Maximum borrowing capacity						50,000,000
Line of Credit | Bridge Loan
Derivative [Line Items]
Maximum borrowing capacity						25,000,000
Foreign Line of Credit | Letter of Credit
Derivative [Line Items]
Maximum borrowing capacity						$ 35,000,000
Subordinated Debt
Derivative [Line Items]
Repayments of debt	$ 291,400,000
Redemption premium		(5,700,000)
Commodity Contracts [Member]
Derivative [Line Items]
Deferred net gains (losses), net of tax, included in AOCI		(1,900,000)		(1,900,000)
Cash Flow Hedging [Member] | Commodity Contracts [Member] | Long [Member]
Derivative [Line Items]
Open option contracts written, at fair value		83,900,000		$ 83,900,000
Time period for open copper future contract purchases				23 months
Fair value of future contracts with net gain (loss) position				$ (2,800,000)
Fair Value Hedging [Member] | Commodity Contracts [Member] | Short [Member]
Derivative [Line Items]
Fair value of future contracts with net gain (loss) position				(2,600,000)
Open future contracts to sell copper		$ 66,700,000		$ 66,700,000
Time period for open copper future contract sales				9 months

Financial Instruments - Summary

Financial Instruments - Summary of Location and Fair Value (Details) - Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Derivatives, Fair Value [Line Items]
Total derivative assets	$ 49	$ 1,205
Total derivative liabilities	(5,497)	(5,795)
Other Current Assets [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Other current assets: Gain positions	132	1,213
Other current assets: Loss positions	(83)	(8)
Other Current Liabilities [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Other current liability: Gain positions	1,788	68
Other current liability: Loss positions	$ (7,285)	$ (5,863)

Financial Instruments - Effects

Financial Instruments - Effects of Derivative Instruments on Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Commodity Contracts [Member] | Cost of Goods Sold [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain on commodity contracts (nonqualifying)	$ (1,893)	$ 5,037	$ (10,423)	$ (4,439)

Financial Instruments - Amounts

Financial Instruments - Amounts Recognized in and Reclassified from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI (Effective Portion), Net of Tax	$ (3,337)	$ 3,398	$ (2,844)	$ 41
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI (Effective Portion), Net of Tax	(1,484)	(1,678)	4	(5,413)
(Gain) Loss Reclassified from AOCI (Effective Portion), Net of Tax	(1,853)	5,076	2,848	(5,454)
Commodity Contracts [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI (Effective Portion), Net of Tax	(1,475)	(1,715)	16	(5,421)
Commodity Contracts [Member] | Cash Flow Hedging [Member] | Cost of Goods Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
(Gain) Loss Reclassified from AOCI (Effective Portion), Net of Tax	(1,853)	5,075	2,849	(5,453)
Other [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in AOCI (Effective Portion), Net of Tax	(9)	37	(12)	8
(Gain) Loss Reclassified from AOCI (Effective Portion), Net of Tax	$ 0	$ 1	$ (1)	$ (1)

Investments in Unconsolidated_3

Investments in Unconsolidated Affiliates - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		66 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021
Schedule of Equity Method Investments [Line Items]
Net income (loss)	$ 110,932	$ 28,487	$ 176,170	$ 62,438
Tecumseh Products Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Interest in the joint venture, ownership percentage	50.00%		50.00%		50.00%
Net income (loss)	$ (1,000)	$ (8,600)	$ (2,700)	$ (15,000)
Second Unconsolidated Affiliate [Member]
Schedule of Equity Method Investments [Line Items]
Interest in the joint venture, ownership percentage	50.00%		50.00%		50.00%
Mueller Middle East [Member]
Schedule of Equity Method Investments [Line Items]
Interest in the joint venture, ownership percentage	40.00%		40.00%		40.00%
Cash invested to acquire joint venture interest					$ 5,000

Investments in Unconsolidated_4

Investments in Unconsolidated Affiliates - Summarized Financial Information Derived from Equity Method Investees' Consolidated Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020	Dec. 26, 2020
Balance sheet data [Abstract]
Current assets	$ 1,081,995		$ 1,081,995		$ 825,361
Current liabilities	362,429		362,429		339,643
Income Statement [Abstract]
Net sales	1,012,592	$ 500,168	1,830,740	$ 1,103,087
Net income (loss)	110,932	28,487	176,170	62,438
Tecumseh
Balance sheet data [Abstract]
Current assets	194,383		194,383		167,451
Noncurrent assets	73,976		73,976		78,241
Current liabilities	145,300		145,300		120,202
Noncurrent liabilities	49,770		49,770		$ 50,020
Income Statement [Abstract]
Net sales	103,834	103,550	201,163	210,548
Gross profit	15,323	11,022	25,022	24,508
Net income (loss)	$ (2,038)	$ (17,282)	$ (5,337)	$ (29,967)

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Pension Benefits [Member]
Components of net periodic benefit cost (income) [Abstract]
Interest cost	$ 313	$ 866	$ 626	$ 1,724
Expected return on plan assets	(904)	(1,495)	(1,808)	(2,990)
Amortization of net loss (gain)	379	528	757	988
Net periodic benefit income	(212)	(101)	(425)	(278)
Other Benefits [Member]
Components of net periodic benefit cost (income) [Abstract]
Interest cost	87	106	174	215
Amortization of net loss (gain)	(33)	(47)	(64)	(100)
Service cost	65	56	130	117
Amortization of prior service credit	(117)	(58)	(235)	(284)
Curtailment gain	0	(2,591)	0	(2,591)
Net periodic benefit income	$ 2	$ (2,534)	$ 5	$ (2,643)

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	1 Months Ended		6 Months Ended	12 Months Ended
	Jan. 31, 2018USD ($)potentially_responsible_partyunilateral_administrative_order	Nov. 27, 2015USD ($)	Jun. 26, 2021USD ($)smelter_siteproperty	Oct. 31, 2008Import_entry	Jun. 26, 2021potentially_responsible_party	Jun. 26, 2021USD ($)	Dec. 26, 2020USD ($)	Mar. 31, 2018action	Nov. 08, 2016USD ($)	Apr. 19, 2010
Loss Contingencies [Line Items]
Term of guarantees			1 year
Payments required to be made under guarantees, maximum						$ 23.9
United States Department of Commerce Antidumping Review [Member]
Loss Contingencies [Line Items]
Assignment of antidumping duty rate on U.S. imports by Company subsidiaries (as a percent)										48.33%
Payment for interest and duties		$ 3
Number of import entries | Import_entry				795
Deepwater Horizon Economic and Property Damage Claim [Member]
Loss Contingencies [Line Items]
Amount awarded to the Company							$ 22.1
Lead Refinery Site [Member]
Loss Contingencies [Line Items]
Financial guarantee									$ 1
Lead Refinery NPL Site [Member]
Loss Contingencies [Line Items]
Environmental reserves	$ 4.5
Number of UAOs | unilateral_administrative_order	2
Number of PRPs | potentially_responsible_party	4
Site contingency, total costs	$ 25
Site contingency, amount agreed upon to pay PRPs for past costs	2
Site contingency, additional reimbursement of past costs	$ 0.7
Contingency charge			$ 7.6
Number of civil tort actions | action								2
Non operating Properties [Member] | Southeast Kansas Sites [Member]
Loss Contingencies [Line Items]
Number of parties involved in settlement negotiations			3		2
Environmental reserves						$ 5.6
Non operating Properties [Member] | Shasta Area Mine Sites [Member]
Loss Contingencies [Line Items]
Period of permit, implementation of Best Management Practices			10 years
Estimated remediation costs, term			30 years
Non operating Properties [Member] | Lead Refinery Site [Member]
Loss Contingencies [Line Items]
Number of parties involved in settlement negotiations | potentially_responsible_party					2
Estimated remediation costs, term			16 years
Amount other PRPs will pay to fund cleanup			$ 26
Number of surrounding properties | property			300
Non operating Properties [Member] | Minimum [Member] | Shasta Area Mine Sites [Member]
Loss Contingencies [Line Items]
Estimated remediation costs			$ 13.9
Non operating Properties [Member] | Minimum [Member] | Lead Refinery Site [Member]
Loss Contingencies [Line Items]
Estimated remediation costs			1.7
Non operating Properties [Member] | Maximum [Member] | Shasta Area Mine Sites [Member]
Loss Contingencies [Line Items]
Estimated remediation costs			18
Non operating Properties [Member] | Maximum [Member] | Lead Refinery Site [Member]
Loss Contingencies [Line Items]
Estimated remediation costs			$ 2.4
Operating Properties [Member] | Mueller Copper Tube Products, Inc. [Member]
Loss Contingencies [Line Items]
Estimated remediation costs, term			5 years
Operating Properties [Member] | Minimum [Member] | Mueller Copper Tube Products, Inc. [Member]
Loss Contingencies [Line Items]
Estimated remediation costs			$ 0.9
Operating Properties [Member] | Maximum [Member] | Mueller Copper Tube Products, Inc. [Member]
Loss Contingencies [Line Items]
Estimated remediation costs			$ 1.1

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Income Tax Disclosure [Abstract]
Effective tax rate	26.00%	26.00%	25.00%	26.00%
Provision for state income taxes, net of federal benefits	$ 5.3	$ 1.2	$ 7.7	$ 3.3
Effect of foreign tax rates differential	$ 1.8		$ 3.1	$ 1.5
Other items		$ 1.3

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Changes in AOCI by Component (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Changes in accumulated other comprehensive income [Roll Forward]
Balance at beginning of period			$ 801,060
Total other comprehensive (loss) income, net	$ (501)	$ (255)	6,275	$ (22,241)
Balance at end of period	973,916		973,916
Cumulative Translation Adjustment [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Balance at beginning of period			(37,339)	(46,198)
Other comprehensive income (loss) before reclassifications			8,248	(19,622)
Amounts reclassified from AOCI			0	0
Total other comprehensive (loss) income, net			8,248	(19,622)
Balance at end of period	(29,091)	(65,820)	(29,091)	(65,820)
Unrealized (Loss) Gain on Derivatives [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Balance at beginning of period			984	476
Other comprehensive income (loss) before reclassifications			4	(5,413)
Amounts reclassified from AOCI			(2,848)	5,454
Total other comprehensive (loss) income, net			(2,844)	41
Balance at end of period	(1,860)	517	(1,860)	517
Pension/OPEB Liability Adjustment [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Balance at beginning of period			(17,203)	(21,855)
Other comprehensive income (loss) before reclassifications			(400)	(1,034)
Amounts reclassified from AOCI			383	489
Total other comprehensive (loss) income, net			(17)	(545)
Balance at end of period	(17,220)	(22,400)	(17,220)	(22,400)
Attributable to Unconsolidated Affiliates [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Balance at beginning of period			(1,325)	(1,193)
Other comprehensive income (loss) before reclassifications			1,234	(903)
Amounts reclassified from AOCI			0	0
Total other comprehensive (loss) income, net			1,234	(903)
Balance at end of period	(91)	(2,096)	(91)	(2,096)
Total [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Balance at beginning of period	(48,528)	(90,165)	(54,883)	(68,770)
Other comprehensive income (loss) before reclassifications			9,086	(26,972)
Amounts reclassified from AOCI			(2,465)	5,943
Total other comprehensive (loss) income, net	266	366	6,621	(21,029)
Balance at end of period	$ (48,262)	$ (89,799)	$ (48,262)	$ (89,799)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Reclassification Adjustments Out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of goods sold	$ 799,712	$ 403,159	$ 1,468,130	$ 911,874
Income tax expense (benefit)	39,006	13,029	60,767	27,173
Net of tax and noncontrolling interests	(108,832)	(27,956)	(171,939)	(60,371)
Other income, net	(683)	(2,834)	(1,260)	(3,112)
Unrealized (gains) losses on derivative commodity contracts [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of goods sold	(2,390)	6,361	(3,689)	6,829
Income tax expense (benefit)	537	(1,285)	841	(1,375)
Net of tax and noncontrolling interests	(1,853)	5,076	(2,848)	5,454
Amortization of net loss and prior service cost on employee benefit plans [Member] | Amount Reclassified from AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)	(38)	(86)	(75)	(115)
Net of tax and noncontrolling interests	191	337	383	489
Other income, net	$ 229	$ 423	$ 458	$ 604