$MLI
MUELLER INDUSTRIES INC Stock $mli

$mli Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000008943921000015 Filed on February 24, 2021

Income Statement

Concept	2020 Q4	2020	2019 Q4
Revenue	$675.9M	$2.398B	$543.8M
YoY Change	24.27%	-1.34%	-2.73%
Cost Of Revenue	$553.5M	$1.966B	$453.3M
YoY Change	22.1%	-3.41%	-6.3%
Gross Profit	$122.3M	$431.9M	$94.36M
YoY Change	29.66%	9.34%	10.84%
Gross Profit Margin	18.1%	18.01%	17.35%
Selling, General & Admin	$44.80M	$159.5M	$40.00M
YoY Change	12.0%	-1.77%	15.61%
% of Gross Profit	36.62%	36.93%	42.39%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$11.70M	$44.84M	$10.60M
YoY Change	10.38%	5.04%	2.91%
% of Gross Profit	9.56%	10.38%	11.23%
Operating Expenses	$56.70M	$159.5M	$51.00M
YoY Change	11.18%	-1.77%	13.33%
Operating Profit	$65.64M	$245.8M	$43.36M
YoY Change	51.4%	28.44%	8.04%
Interest Expense	-$4.000M	$19.25M	-$1.600M
YoY Change	150.0%	-25.06%	-148.48%
% of Operating Profit	-6.09%	7.83%	-3.69%
Other Income/Expense, Net	-$3.200M	$4.887M	-$500.0K
YoY Change	540.0%	190.2%	-145.45%
Pretax Income	$40.00M	$209.2M	$38.40M
YoY Change	4.17%	25.95%	10.98%
Income Tax	$12.70M	$55.32M	$7.600M
% Of Pretax Income	31.75%	26.45%	19.79%
Net Earnings	$36.42M	$139.5M	$28.17M
YoY Change	29.29%	38.15%	4.89%
Net Earnings / Revenue	5.39%	5.82%	5.18%
Basic Earnings Per Share	$0.65	$2.50	$0.50
Diluted Earnings Per Share	$0.64	$2.47	$0.50
COMMON SHARES
Basic Shares Outstanding	57.08M shares	55.82M shares	56.95M shares
Diluted Shares Outstanding		56.39M shares

Balance Sheet

Concept	2020 Q4	2020	2019 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$119.1M	$119.1M	$97.90M
YoY Change	21.65%	21.65%	34.85%
Cash & Equivalents	$119.1M	$119.1M	$97.94M
Short-Term Investments
Other Short-Term Assets	$33.75M	$33.80M	$33.78M
YoY Change	-0.08%	0.0%	26.08%
Inventory	$315.0M	$315.0M	$292.1M
Prepaid Expenses
Receivables	$357.5M	$357.5M	$269.9M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$825.4M	$825.4M	$693.8M
YoY Change	18.97%	18.97%	-1.26%
LONG-TERM ASSETS
Property, Plant & Equipment	$376.6M	$405.9M	$363.1M
YoY Change	3.7%	4.05%	-2.02%
Goodwill	$167.8M		$153.3M
YoY Change	9.45%		1.96%
Intangibles	$77.21M		$60.08M
YoY Change	28.5%		-3.05%
Long-Term Investments	$38.00M	$38.00M	$48.40M
YoY Change	-21.49%	-21.49%	-16.55%
Other Assets	$14.39M	$14.40M	$25.40M
YoY Change	-43.35%	-43.31%	-2.13%
Total Long-Term Assets	$703.2M	$703.2M	$677.2M
YoY Change	3.85%	3.85%	1.53%
TOTAL ASSETS
Total Short-Term Assets	$825.4M	$825.4M	$693.8M
Total Long-Term Assets	$703.2M	$703.2M	$677.2M
Total Assets	$1.529B	$1.529B	$1.371B
YoY Change	11.5%	11.5%	0.1%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$147.7M	$147.7M	$85.64M
YoY Change	72.51%	72.55%	-17.45%
Accrued Expenses	$52.60M	$120.4M	$46.90M
YoY Change	12.15%	12.73%	21.82%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$41.28M	$41.30M	$7.530M
YoY Change	448.25%	450.67%	6.06%
Total Short-Term Liabilities	$339.6M	$339.6M	$234.3M
YoY Change	44.97%	44.94%	0.64%
LONG-TERM LIABILITIES
Long-Term Debt	$286.6M	$286.6M	$378.7M
YoY Change	-24.33%	-24.32%	-22.65%
Other Long-Term Liabilities	$14.73M	$84.40M	$10.13M
YoY Change	45.41%	12.99%	-44.37%
Total Long-Term Liabilities	$301.3M	$371.0M	$388.9M
YoY Change	-22.51%	-18.17%	-23.42%
TOTAL LIABILITIES
Total Short-Term Liabilities	$339.6M	$339.6M	$234.3M
Total Long-Term Liabilities	$301.3M	$371.0M	$388.9M
Total Liabilities	$727.5M	$751.8M	$708.8M
YoY Change	2.64%	3.34%	-12.09%
SHAREHOLDERS EQUITY
Retained Earnings	$1.020B		$903.1M
YoY Change	12.91%		9.5%
Common Stock	$802.0K		$802.0K
YoY Change	0.0%		0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$468.9M		$470.2M
YoY Change	-0.28%		-0.84%
Treasury Stock Shares	6.400M shares		6.200M shares
Shareholders Equity	$776.7M	$776.7M	$643.5M
YoY Change
Total Liabilities & Shareholders Equity	$1.529B	$1.529B	$1.371B
YoY Change	11.5%	11.5%	0.1%

Cashflow Statement

Concept	2020 Q4	2020	2019 Q4
OPERATING ACTIVITIES
Net Income	$36.42M	$139.5M	$28.17M
YoY Change	29.29%	38.15%	4.89%
Depreciation, Depletion And Amortization	$11.70M	$44.84M	$10.60M
YoY Change	10.38%	5.04%	2.91%
Cash From Operating Activities	$48.20M	$245.1M	$68.60M
YoY Change	-29.74%	22.2%	51.1%
INVESTING ACTIVITIES
Capital Expenditures	-$14.70M	-$43.90M	-$11.00M
YoY Change	33.64%	40.71%	-49.54%
Acquisitions		$72.65M
YoY Change		-2196.62%
Other Investing Activities	$100.0K	-$81.70M	-$2.100M
YoY Change	-104.76%	778.49%	-310.0%
Cash From Investing Activities	-$14.60M	-$125.6M	-$13.20M
YoY Change	10.61%	210.51%	-36.54%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$5.574M
YoY Change		216.17%
Debt Paid & Issued, Net		$246.9M
YoY Change		19.44%
Cash From Financing Activities	-26.00M	-$92.26M	-62.00M
YoY Change	-58.06%	-33.95%	12.73%
NET CHANGE
Cash From Operating Activities	48.20M	$245.1M	68.60M
Cash From Investing Activities	-14.60M	-$125.6M	-13.20M
Cash From Financing Activities	-26.00M	-$92.26M	-62.00M
Net Change In Cash	7.600M	$29.33M	-6.600M
YoY Change	-215.15%	40.33%	-78.29%
FREE CASH FLOW
Cash From Operating Activities	$48.20M	$245.1M	$68.60M
Capital Expenditures	-$14.70M	-$43.90M	-$11.00M
Free Cash Flow	$62.90M	$289.0M	$79.60M
YoY Change	-20.98%	24.69%	18.45%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0000089439
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2018	mli	Earnings Loss Per Diluted Share Impact Of Tax Cuts And Jobs Act Transition Tax On Accumulated Foreign Earnings EarningsLossPerDilutedShareImpactOfTaxCutsAndJobsActTransitionTaxOnAccumulatedForeignEarnings	-0.08
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-26
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-26
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	1-6770
CY2020	dei	Entity Registrant Name EntityRegistrantName	MUELLER INDUSTRIES, INC.
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	25-0790410
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	150 Schilling Boulevard
CY2020	dei	Entity Address Address Line2 EntityAddressAddressLine2	Suite 100
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Collierville
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	TN
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	38017
CY2020	dei	City Area Code CityAreaCode	901
CY2020	dei	Local Phone Number LocalPhoneNumber	753-3200
CY2020	dei	Security12b Title Security12bTitle	Common Stock, $0.01 Par Value
CY2020	dei	Trading Symbol TradingSymbol	MLI
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2020	dei	Entity Small Business EntitySmallBusiness	false
CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2020	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2020	dei	Entity Shell Company EntityShellCompany	false
CY2020Q2	dei	Entity Public Float EntityPublicFloat	1346053993	USD
CY2021Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	57115648	shares
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2398043000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2430616000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2507878000	USD
CY2020	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1966161000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	2035610000	USD
CY2018	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	2150400000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	44843000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	42693000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	39555000	USD
CY2020	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	159483000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	162358000	USD
CY2018	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	148888000	USD
CY2020	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	22053000	USD
CY2019	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	0	USD
CY2018	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	0	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	963000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	253000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	3771000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2020	us-gaap	Insurance Recoveries InsuranceRecoveries	0	USD
CY2019	us-gaap	Insurance Recoveries InsuranceRecoveries	485000	USD
CY2018	us-gaap	Insurance Recoveries InsuranceRecoveries	3681000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	245838000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	191403000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	172969000	USD
CY2020	us-gaap	Interest Expense InterestExpense	19247000	USD
CY2019	us-gaap	Interest Expense InterestExpense	25683000	USD
CY2018	us-gaap	Interest Expense InterestExpense	25199000	USD
CY2020	mli	Environmental Remediation Expense Non Operating Properties EnvironmentalRemediationExpenseNonOperatingProperties	4454000	USD
CY2019	mli	Environmental Remediation Expense Non Operating Properties EnvironmentalRemediationExpenseNonOperatingProperties	1321000	USD
CY2018	mli	Environmental Remediation Expense Non Operating Properties EnvironmentalRemediationExpenseNonOperatingProperties	1320000	USD
CY2020	mli	Defined Benefit Plans Termination Expenses DefinedBenefitPlansTerminationExpenses	17835000	USD
CY2019	mli	Defined Benefit Plans Termination Expenses DefinedBenefitPlansTerminationExpenses	0	USD
CY2018	mli	Defined Benefit Plans Termination Expenses DefinedBenefitPlansTerminationExpenses	0	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	4887000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	1684000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	3967000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	209189000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	166083000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	150417000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	55321000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	35257000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30952000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-10219000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-24594000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-12645000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	143649000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	106232000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	106820000	USD
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	4156000	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	5260000	USD
CY2018	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	2361000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	139493000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	100972000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	104459000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	55821000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	55798000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56782000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	569000	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	545000	shares
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	487000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	56390000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	56343000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57269000	shares
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.50
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.81
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.84
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.47
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.79
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.82
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2020	us-gaap	Profit Loss ProfitLoss	143649000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	106232000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	106820000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	10350000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	7409000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-16876000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	146000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	195000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-318000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	508000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	690000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-1173000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-1560000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-671000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	670000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-4652000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-3112000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	3339000	USD
CY2020	mli	Other Comprehensive Income Loss Attributable To Unconsolidated Affiliates Tax OtherComprehensiveIncomeLossAttributableToUnconsolidatedAffiliatesTax	-38000	USD
CY2019	mli	Other Comprehensive Income Loss Attributable To Unconsolidated Affiliates Tax OtherComprehensiveIncomeLossAttributableToUnconsolidatedAffiliatesTax	-244000	USD
CY2018	mli	Other Comprehensive Income Loss Attributable To Unconsolidated Affiliates Tax OtherComprehensiveIncomeLossAttributableToUnconsolidatedAffiliatesTax	-2522000	USD
CY2020	mli	Other Comprehensive Income Loss Attributable To Unconsolidated Affiliates Net Of Tax Including Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossAttributableToUnconsolidatedAffiliatesNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-132000	USD
CY2019	mli	Other Comprehensive Income Loss Attributable To Unconsolidated Affiliates Net Of Tax Including Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossAttributableToUnconsolidatedAffiliatesNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-839000	USD
CY2018	mli	Other Comprehensive Income Loss Attributable To Unconsolidated Affiliates Net Of Tax Including Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossAttributableToUnconsolidatedAffiliatesNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-8686000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	15378000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	10372000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-30074000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	159027000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	116604000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	76746000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	5647000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	4610000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	1579000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	153380000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	111994000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	75167000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	119075000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	97944000	USD
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1538000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	770000	USD
CY2020Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	357532000	USD
CY2019Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	269943000	USD
CY2020Q4	us-gaap	Inventory Net InventoryNet	315002000	USD
CY2019Q4	us-gaap	Inventory Net InventoryNet	292107000	USD
CY2020Q4	us-gaap	Other Assets Current OtherAssetsCurrent	33752000	USD
CY2019Q4	us-gaap	Other Assets Current OtherAssetsCurrent	33778000	USD
CY2020Q4	us-gaap	Assets Current AssetsCurrent	825361000	USD
CY2019Q4	us-gaap	Assets Current AssetsCurrent	693772000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	376572000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	363128000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	29301000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	26922000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	167764000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	153276000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	77207000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	60082000	USD
CY2020Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	37976000	USD
CY2019Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	48363000	USD
CY2020Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	14387000	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	25397000	USD
CY2020Q4	us-gaap	Assets Assets	1528568000	USD
CY2019Q4	us-gaap	Assets Assets	1370940000	USD
CY2020Q4	us-gaap	Debt Current DebtCurrent	41283000	USD
CY2019Q4	us-gaap	Debt Current DebtCurrent	7530000	USD
CY2020Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	147741000	USD
CY2019Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	85644000	USD
CY2020Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	46299000	USD
CY2019Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	41673000	USD
CY2020Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	6259000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	5250000	USD
CY2020Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	98061000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	94190000	USD
CY2020Q4	us-gaap	Liabilities Current LiabilitiesCurrent	339643000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	234287000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	286593000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	378724000	USD
CY2020Q4	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	13552000	USD
CY2019Q4	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	9126000	USD
CY2020Q4	us-gaap	Other Postretirement Defined Benefit Plan Liabilities Noncurrent OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent	13289000	USD
CY2019Q4	us-gaap	Other Postretirement Defined Benefit Plan Liabilities Noncurrent OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent	13082000	USD
CY2020Q4	us-gaap	Accrued Environmental Loss Contingencies Noncurrent AccruedEnvironmentalLossContingenciesNoncurrent	21256000	USD
CY2019Q4	us-gaap	Accrued Environmental Loss Contingencies Noncurrent AccruedEnvironmentalLossContingenciesNoncurrent	19972000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	16842000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	21094000	USD
CY2020Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	21602000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	22388000	USD
CY2020Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	14731000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	10131000	USD
CY2020Q4	us-gaap	Liabilities Liabilities	727508000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	708804000	USD
CY2020Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1.00
CY2019Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1.00
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	5000000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	5000000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2020Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2020Q4	us-gaap	Minority Interest MinorityInterest	24315000	USD
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	80183004	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	80183004	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	57087432	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	56949246	shares
CY2020Q4	us-gaap	Common Stock Value CommonStockValue	802000	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	802000	USD
CY2020Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	280051000	USD
CY2019Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	278609000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1019694000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	903070000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-54883000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-68770000	USD
CY2020Q4	us-gaap	Treasury Stock Value TreasuryStockValue	468919000	USD
CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	470243000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	776745000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	643468000	USD
CY2020Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies	0	USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies	0	USD
CY2019Q4	us-gaap	Minority Interest MinorityInterest	18668000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	801060000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	662136000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1528568000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1370940000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	143649000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	106232000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	106820000	USD
CY2020	us-gaap	Depreciation Depreciation	38715000	USD
CY2019	us-gaap	Depreciation Depreciation	37337000	USD
CY2018	us-gaap	Depreciation Depreciation	35118000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6128000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5356000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4437000	USD
CY2020	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	319000	USD
CY2019	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	318000	USD
CY2018	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	318000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-10219000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-24594000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-12645000	USD
CY2020	us-gaap	Proceeds From Insurance Premiums Collected ProceedsFromInsurancePremiumsCollected	0	USD
CY2019	us-gaap	Proceeds From Insurance Premiums Collected ProceedsFromInsurancePremiumsCollected	485000	USD
CY2018	us-gaap	Proceeds From Insurance Premiums Collected ProceedsFromInsurancePremiumsCollected	2306000	USD
CY2020	mli	Business Combination Change In Fair Value Of Contingent Consideration BusinessCombinationChangeInFairValueOfContingentConsideration	0	USD
CY2019	mli	Business Combination Change In Fair Value Of Contingent Consideration BusinessCombinationChangeInFairValueOfContingentConsideration	3625000	USD
CY2018	mli	Business Combination Change In Fair Value Of Contingent Consideration BusinessCombinationChangeInFairValueOfContingentConsideration	0	USD
CY2020	us-gaap	Insurance Recoveries InsuranceRecoveries	0	USD
CY2019	us-gaap	Insurance Recoveries InsuranceRecoveries	485000	USD
CY2018	us-gaap	Insurance Recoveries InsuranceRecoveries	3681000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	8570000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	8744000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	8035000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	1208000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-80000	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-286000	USD
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-11642000	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2018	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2020	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-132000	USD
CY2019	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	963000	USD
CY2018	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	253000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	3771000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4046000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-428000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	170000	USD
CY2020	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	76404000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-6585000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	11056000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-5207000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-39561000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-27512000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-20609000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	15639000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-14353000	USD
CY2020	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	74097000	USD
CY2019	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	-7076000	USD
CY2018	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	-15680000	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-1142000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-7944000	USD
CY2018	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-14769000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-2399000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-322000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-1903000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	245073000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	200544000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	167892000	USD
CY2020	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	181000	USD
CY2019	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	3240000	USD
CY2018	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	18703000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	72648000	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	-3465000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	167677000	USD
CY2020	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	43885000	USD
CY2019	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	31162000	USD
CY2018	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	38481000	USD
CY2020	us-gaap	Payments To Acquire Notes Receivable PaymentsToAcquireNotesReceivable	9270000	USD
CY2019	us-gaap	Payments To Acquire Notes Receivable PaymentsToAcquireNotesReceivable	0	USD
CY2018	us-gaap	Payments To Acquire Notes Receivable PaymentsToAcquireNotesReceivable	0	USD
CY2020	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	0	USD
CY2019	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	0	USD
CY2018	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	1968000	USD
CY2020	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	0	USD
CY2019	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	16000000	USD
CY2018	us-gaap	Payments To Acquire Interest In Subsidiaries And Affiliates PaymentsToAcquireInterestInSubsidiariesAndAffiliates	1609000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-125622000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-40457000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-187096000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	22341000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	22325000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	22705000	USD
CY2020	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	0	USD
CY2019	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	846000	USD
CY2018	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	592000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	190038000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	100658000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	204233000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	246898000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	206718000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	172002000	USD
CY2020	us-gaap	Repayments Of Debt RepaymentsOfDebt	259000	USD
CY2019	us-gaap	Repayments Of Debt RepaymentsOfDebt	4305000	USD
CY2018	us-gaap	Repayments Of Debt RepaymentsOfDebt	2915000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	5574000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1763000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	33562000	USD
CY2020	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	7000000	USD
CY2019	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	3170000	USD
CY2018	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	0	USD
CY2020	mli	Payments For Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options PaymentsForIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	230000	USD
CY2019	mli	Payments For Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options PaymentsForIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	1225000	USD
CY2018	mli	Payments For Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options PaymentsForIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	726000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-92264000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-139694000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-28269000	USD
CY2020	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2147000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	511000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-1952000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	29334000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	20904000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-49425000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98042000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	77138000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	126563000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	127376000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98042000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	77138000	USD
CY2020	us-gaap	Fiscal Period FiscalPeriod	<div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Fiscal Years</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The Company’s fiscal year consists of 52 weeks ending on the last Saturday of December. These dates were December 26, 2020, December 28, 2019, and December 29, 2018.</span></div>
CY2020Q4	mli	Temporary Investments TemporaryInvestments	13300000	USD
CY2019Q4	mli	Temporary Investments TemporaryInvestments	500000	USD
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1500000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	800000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Renewal Term LesseeOperatingLeaseRenewalTerm	P5Y
CY2020	mli	Specified Percentage Over Which Unrecognized Gains And Losses Are Amortized SpecifiedPercentageOverWhichUnrecognizedGainsAndLossesAreAmortized	0.10
CY2020	mli	Average Remaining Service Period For The Pension Plans AverageRemainingServicePeriodForThePensionPlans	P11Y6M
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	10000	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2020	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Concentrations of Credit and Market Risk</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Concentrations of credit risk with respect to accounts receivable are limited due to the large number of customers comprising the Company’s customer base, and their dispersion across different geographic areas and different industries, including HVAC, plumbing, refrigeration, hardware, automotive, OEMs, and others.</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The Company minimizes its exposure to base metal price fluctuations through various strategies. Generally, it prices an equivalent amount of copper raw material, under flexible pricing arrangements it maintains with its suppliers, at the time it determines the selling price of finished products to its customers.</span></div>
CY2020	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-500000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	200000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-1000000.0	USD
CY2020	us-gaap	Use Of Estimates UseOfEstimates	<div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Use of and Changes in Estimates</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The preparation of financial statements in conformity with generally accepted accounting principles in the United States (U.S. GAAP) requires management to make estimates, assumptions, and judgments that affect the amounts reported in the financial statements and accompanying notes. </span><span style="color:#252525;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Management makes its best estimate of the ultimate outcome for these items based on historical trends and other information available when the financial statements are prepared. Changes in estimates are recognized in accordance with the accounting rules for the estimate, which is typically in the period when new information becomes available to management. Areas where the nature of the estimate makes it reasonably possible that actual results could materially differ from amounts estimated include but are not limited to: pension and other postretirement benefit plan obligations, tax liabilities, loss contingencies, litigation claims, environmental reserves, and impairment assessments of long-lived assets (including goodwill).</span></div>
CY2019Q4	us-gaap	Noncurrent Assets NoncurrentAssets	363128000	USD
CY2018Q4	us-gaap	Noncurrent Assets NoncurrentAssets	370633000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2398043000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2430616000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2507878000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2398043000	USD
CY2020	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1966161000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	44843000	USD
CY2020	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	159483000	USD
CY2020	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	22053000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	3771000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	245838000	USD
CY2020	us-gaap	Interest Expense InterestExpense	19247000	USD
CY2020	mli	Defined Benefit Plans Termination Expenses DefinedBenefitPlansTerminationExpenses	17835000	USD
CY2020	mli	Environmental Remediation Expense Non Operating Properties EnvironmentalRemediationExpenseNonOperatingProperties	4454000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	4887000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	209189000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2430616000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	172969000	USD
CY2018	us-gaap	Interest Expense InterestExpense	25199000	USD
CY2018	mli	Environmental Remediation Expense Non Operating Properties EnvironmentalRemediationExpenseNonOperatingProperties	1320000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	3967000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	150417000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2398043000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2430616000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2507878000	USD
CY2020Q4	us-gaap	Noncurrent Assets NoncurrentAssets	376572000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	2035610000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	42693000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	162358000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	963000	USD
CY2019	us-gaap	Insurance Recoveries InsuranceRecoveries	485000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	191403000	USD
CY2019	us-gaap	Interest Expense InterestExpense	25683000	USD
CY2019	mli	Environmental Remediation Expense Non Operating Properties EnvironmentalRemediationExpenseNonOperatingProperties	1321000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	1684000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	166083000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2507878000	USD
CY2018	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	2150400000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	39555000	USD
CY2018	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	148888000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	253000	USD
CY2018	us-gaap	Insurance Recoveries InsuranceRecoveries	3681000	USD
CY2020	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	51146000	USD
CY2019	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	31162000	USD
CY2018	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	124936000	USD
CY2020Q4	us-gaap	Assets Assets	1528568000	USD
CY2019Q4	us-gaap	Assets Assets	1370940000	USD
CY2018Q4	us-gaap	Assets Assets	1369549000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	119075000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	97944000	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	7600000	USD
CY2019Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	200000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	29301000	USD
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y4M6D
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	7039000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	6818000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	4734000	USD
CY2019	us-gaap	Short Term Lease Cost ShortTermLeaseCost	4951000	USD
CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	8198000	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	0	USD
CY2020Q4	us-gaap	Restricted Cash Equivalents Noncurrent RestrictedCashEquivalentsNoncurrent	103000	USD
CY2019Q4	us-gaap	Restricted Cash Equivalents Noncurrent RestrictedCashEquivalentsNoncurrent	98000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	127376000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98042000	USD
CY2020Q4	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	85927000	USD
CY2019Q4	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	85769000	USD
CY2020Q4	us-gaap	Inventory Work In Process InventoryWorkInProcess	49361000	USD
CY2019Q4	us-gaap	Inventory Work In Process InventoryWorkInProcess	48814000	USD
CY2020Q4	us-gaap	Inventory Finished Goods InventoryFinishedGoods	186785000	USD
CY2019Q4	us-gaap	Inventory Finished Goods InventoryFinishedGoods	163842000	USD
CY2020Q4	us-gaap	Inventory Adjustments InventoryAdjustments	7071000	USD
CY2019Q4	us-gaap	Inventory Adjustments InventoryAdjustments	6318000	USD
CY2020Q4	us-gaap	Inventory Net InventoryNet	315002000	USD
CY2019Q4	us-gaap	Inventory Net InventoryNet	292107000	USD
CY2020Q4	us-gaap	Lifo Inventory Amount LIFOInventoryAmount	17300000	USD
CY2019Q4	us-gaap	Lifo Inventory Amount LIFOInventoryAmount	16800000	USD
CY2020Q4	us-gaap	Fifo Inventory Amount FIFOInventoryAmount	108100000	USD
CY2019Q4	us-gaap	Fifo Inventory Amount FIFOInventoryAmount	87800000	USD
CY2020Q4	mli	Fifo Value Of Inventory Consigned To Others FifoValueOfInventoryConsignedToOthers	6400000	USD
CY2019Q4	mli	Fifo Value Of Inventory Consigned To Others FifoValueOfInventoryConsignedToOthers	5500000	USD
CY2020Q4	mli	Accrued Discounts And Allowances Liability Current AccruedDiscountsAndAllowancesLiabilityCurrent	56000000.0	USD
CY2020	mli	Environmental Expense Non Operating Properties EnvironmentalExpenseNonOperatingProperties	2700000	USD
CY2019	mli	Environmental Expense Non Operating Properties EnvironmentalExpenseNonOperatingProperties	900000	USD
CY2019Q4	mli	Accrued Discounts And Allowances Liability Current AccruedDiscountsAndAllowancesLiabilityCurrent	53900000	USD
CY2020Q4	us-gaap	Deposit Liabilities Accrued Interest DepositLiabilitiesAccruedInterest	5400000	USD
CY2019Q4	us-gaap	Deposit Liabilities Accrued Interest DepositLiabilitiesAccruedInterest	6000000.0	USD
CY2020Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	6300000	USD
CY2019Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	4700000	USD
CY2020Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	6300000	USD
CY2019Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	200000	USD
CY2020Q4	us-gaap	Sales And Excise Tax Payable Current SalesAndExciseTaxPayableCurrent	6400000	USD
CY2019Q4	us-gaap	Business Combination Contingent Consideration Liability Current BusinessCombinationContingentConsiderationLiabilityCurrent	7000000.0	USD
CY2020	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-3013000	USD
CY2019	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-465000	USD
CY2018	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-2914000	USD
CY2020	us-gaap	Interest Income Other InterestIncomeOther	1101000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	26922000	USD
CY2020Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	6259000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	5250000	USD
CY2020Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	21602000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	22388000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	27861000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	27638000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0391
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0582
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P5Y11M26D
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	4887000	USD
CY2020	us-gaap	Lease Cost LeaseCost	11773000	USD
CY2019	us-gaap	Interest Income Other InterestIncomeOther	722000	USD
CY2018	us-gaap	Interest Income Other InterestIncomeOther	624000	USD
CY2020	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	773000	USD
CY2019	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	497000	USD
CY2018	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	429000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	1684000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	3967000	USD
CY2019	us-gaap	Lease Cost LeaseCost	11769000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	7040000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	6703000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	7353000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	6489000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	4553000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	3382000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	2376000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	7254000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	31407000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	3546000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	27861000	USD
CY2020Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	6259000	USD
CY2020Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	21602000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	939165000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	895311000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	562593000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	532183000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	376572000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	363128000	USD
CY2020	us-gaap	Depreciation Depreciation	38700000	USD
CY2019	us-gaap	Depreciation Depreciation	37300000	USD
CY2018	us-gaap	Depreciation Depreciation	35100000	USD
CY2019	us-gaap	Goodwill Other Increase Decrease GoodwillOtherIncreaseDecrease	-534000	USD
CY2019	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	1476000	USD
CY2018Q4	us-gaap	Goodwill Gross GoodwillGross	199740000	USD
CY2018Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	49405000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	150335000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	1999000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	153276000	USD
CY2020	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	13674000	USD
CY2020	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	814000	USD
CY2020Q4	us-gaap	Goodwill Gross GoodwillGross	217169000	USD
CY2020Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	49405000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	167764000	USD
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2019	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2018	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2020	us-gaap	Adjustment For Amortization AdjustmentForAmortization	6100000	USD
CY2019	us-gaap	Adjustment For Amortization AdjustmentForAmortization	5400000	USD
CY2018	us-gaap	Adjustment For Amortization AdjustmentForAmortization	4400000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	6393000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	6311000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	6000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	5769000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	5743000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	46991000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	77207000	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	274000	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	150000	USD
CY2020Q4	mli	Long Term Debt Including Unamortized Discount Premium And Debt Issuance Costs LongTermDebtIncludingUnamortizedDiscountPremiumAndDebtIssuanceCosts	328095000	USD
CY2019Q4	mli	Long Term Debt Including Unamortized Discount Premium And Debt Issuance Costs LongTermDebtIncludingUnamortizedDiscountPremiumAndDebtIssuanceCosts	386792000	USD
CY2020Q4	us-gaap	Debt Issuance Costs Line Of Credit Arrangements Net DebtIssuanceCostsLineOfCreditArrangementsNet	219000	USD
CY2019Q4	us-gaap	Debt Issuance Costs Line Of Credit Arrangements Net DebtIssuanceCostsLineOfCreditArrangementsNet	538000	USD
CY2020Q4	us-gaap	Debt Current DebtCurrent	41283000	USD
CY2019Q4	us-gaap	Debt Current DebtCurrent	7530000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	286593000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	378724000	USD
CY2017Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	3.00
CY2017Q1	mli	Common Stock Dividends Per Share Paid In Kind CommonStockDividendsPerSharePaidInKind	5.00
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	41283000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	222000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	222000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	222000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	167000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	285979000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	328095000	USD
CY2020	us-gaap	Interest Expense Debt InterestExpenseDebt	19510000	USD
CY2019	us-gaap	Interest Expense Debt InterestExpenseDebt	25957000	USD
CY2018	us-gaap	Interest Expense Debt InterestExpenseDebt	25349000	USD
CY2020	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	263000	USD
CY2020	us-gaap	Interest Expense InterestExpense	19247000	USD
CY2019	us-gaap	Interest Expense InterestExpense	25683000	USD
CY2018	us-gaap	Interest Expense InterestExpense	25199000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	19800000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	25400000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	25200000	USD
CY2020	mli	Defined Benefit Plan Plan Termination Incremental Benefit Payments DefinedBenefitPlanPlanTerminationIncrementalBenefitPayments	100000000.0	USD
CY2020	mli	Defined Benefit Plan Plan Assets Surplus Assets DefinedBenefitPlanPlanAssetsSurplusAssets	12400000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Amortization Of Gain Loss Next Fiscal Year DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear	-900000	USD
CY2020	mli	Payable Maximum Period To Be Considered Current PayableMaximumPeriodToBeConsideredCurrent	P12M
CY2020Q4	us-gaap	Defined Benefit Plan Ultimate Health Care Cost Trend Rate1 DefinedBenefitPlanUltimateHealthCareCostTrendRate1	0.041
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	78480000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	183486000	USD
CY2020Q4	mli	Approximate Percentage Of Mutual Funds Actively Managed ApproximatePercentageOfMutualFundsActivelyManaged	0.76
CY2020Q4	mli	Approximate Percentage Of Mutual Funds Indexed Funds ApproximatePercentageOfMutualFundsIndexedFunds	0.24
CY2020Q4	mli	Percentage Of Mutual Funds Assets Invested In Us Equities PercentageOfMutualFundsAssetsInvestedInUSEquities	0.27
CY2020Q4	mli	Percent Of Mutual Funds Assets Invested In Non Us Equities PercentOfMutualFundsAssetsInvestedInNonUsEquities	0.73
CY2019Q4	mli	Approximate Percentage Of Mutual Funds Actively Managed ApproximatePercentageOfMutualFundsActivelyManaged	0.80
CY2019Q4	mli	Approximate Percentage Of Mutual Funds Indexed Funds ApproximatePercentageOfMutualFundsIndexedFunds	0.20
CY2019Q4	mli	Percentage Of Mutual Funds Assets Invested In Us Equities PercentageOfMutualFundsAssetsInvestedInUSEquities	0.10
CY2019Q4	mli	Percent Of Mutual Funds Assets Invested In Non Us Equities PercentOfMutualFundsAssetsInvestedInNonUsEquities	0.28
CY2019Q4	mli	Percent Of Mutual Funds Assets Invested In Us Fixed Income Securities PercentOfMutualFundsAssetsInvestedInUSFixedIncomeSecurities	0.62
CY2020Q4	mli	Number Of Collective Bargaining Agreements NumberOfCollectiveBargainingAgreements	2	bargain_agreement
CY2020	us-gaap	Multiemployer Plan Employer Contribution Cost MultiemployerPlanEmployerContributionCost	1200000	USD
CY2019	us-gaap	Multiemployer Plan Employer Contribution Cost MultiemployerPlanEmployerContributionCost	1200000	USD
CY2018	us-gaap	Multiemployer Plan Employer Contribution Cost MultiemployerPlanEmployerContributionCost	1300000	USD
CY2020	mli	Maximum Percentage Of Employer Contributions MaximumPercentageOfEmployerContributions	0.05
CY2020	mli	Multiemployer Plans Funded Status Percent MultiemployerPlansFundedStatusPercent	0.80
CY2019	mli	Multiemployer Plans Funded Status Percent MultiemployerPlansFundedStatusPercent	0.89
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	5700000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	5400000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	5100000	USD
CY2020	mli	Coal Industry Retiree Health Benefit Act Of1992 Plan Contributions CoalIndustryRetireeHealthBenefitActOf1992PlanContributions	57000	USD
CY2019	mli	Coal Industry Retiree Health Benefit Act Of1992 Plan Contributions CoalIndustryRetireeHealthBenefitActOf1992PlanContributions	223000	USD
CY2018	mli	Coal Industry Retiree Health Benefit Act Of1992 Plan Contributions CoalIndustryRetireeHealthBenefitActOf1992PlanContributions	153000	USD
CY2020	us-gaap	Environmental Remediation Expense EnvironmentalRemediationExpense	4200000	USD
CY2019	us-gaap	Environmental Remediation Expense EnvironmentalRemediationExpense	1700000	USD
CY2018	us-gaap	Environmental Remediation Expense EnvironmentalRemediationExpense	2000000.0	USD
CY2020Q4	us-gaap	Accrual For Environmental Loss Contingencies AccrualForEnvironmentalLossContingencies	24000000.0	USD
CY2019Q4	us-gaap	Accrual For Environmental Loss Contingencies AccrualForEnvironmentalLossContingencies	20900000	USD
CY2020Q4	us-gaap	Accrual For Environmental Loss Contingencies Undiscounted Due Within One Year AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear	2700000	USD
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CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	112812000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	105455000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	64419000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	53271000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	44962000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	209189000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	166083000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	150417000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	37964000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	19066000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	17974000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	16221000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	12727000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	9650000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	5182000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	3892000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	3158000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	59367000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	35685000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	30782000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-5991000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	1725000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-1381000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	90000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-2311000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	551000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1855000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	158000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1000000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4046000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-428000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	170000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	55321000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	35257000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30952000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	43930000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	34892000	USD
CY2020	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	2783000	USD
CY2019	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	-771000	USD
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	31588000	USD
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	5949000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	3234000	USD
CY2018	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	3495000	USD
CY2018	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	759000	USD
CY2020	mli	Income Tax Rate Reconciliation Investment In Unconsolidated Affiliates IncomeTaxRateReconciliationInvestmentInUnconsolidatedAffiliates	387000	USD
CY2019	mli	Income Tax Rate Reconciliation Investment In Unconsolidated Affiliates IncomeTaxRateReconciliationInvestmentInUnconsolidatedAffiliates	-538000	USD
CY2018	mli	Income Tax Rate Reconciliation Investment In Unconsolidated Affiliates IncomeTaxRateReconciliationInvestmentInUnconsolidatedAffiliates	2776000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Transition Tax On Accumulated Foreign Earnings Amount EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsAmount	0	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Transition Tax On Accumulated Foreign Earnings Amount EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsAmount	-111000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Transition Tax On Accumulated Foreign Earnings Amount EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsAmount	-4415000	USD
CY2020	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	3046000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-2525000	USD
CY2018	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	2301000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	55321000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	35257000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30952000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Of2017 Transition Tax On Accumulated Foreign Earnings Amount EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsAmount	-4400000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Inventory DeferredTaxAssetsInventory	13910000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Inventory DeferredTaxAssetsInventory	12247000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	11477000	USD
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CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther	7782000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther	6834000	USD
CY2020Q4	mli	Deferred Tax Asset Tax Credit Federal And Foreign DeferredTaxAssetTaxCreditFederalAndForeign	6250000	USD
CY2019Q4	mli	Deferred Tax Asset Tax Credit Federal And Foreign DeferredTaxAssetTaxCreditFederalAndForeign	5909000	USD
CY2020Q4	mli	Deferred Tax Asset Tax Credit State And Local DeferredTaxAssetTaxCreditStateAndLocal	21178000	USD
CY2019Q4	mli	Deferred Tax Asset Tax Credit State And Local DeferredTaxAssetTaxCreditStateAndLocal	22395000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	3751000	USD
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CY2019Q4	mli	Deferred Tax Assets Operating Lease Liability DeferredTaxAssetsOperatingLeaseLiability	5965000	USD
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CY2020Q4	mli	State Tax Credits And Net Operating Carryforwards Offset By Valuation Allowances StateTaxCreditsAndNetOperatingCarryforwardsOffsetByValuationAllowances	12000000.0	USD
CY2020Q4	mli	Federal And Foreign Tax Attributes With Potential Tax Benefits Unlimited Life FederalAndForeignTaxAttributesWithPotentialTaxBenefitsUnlimitedLife	4600000	USD
CY2020Q4	mli	Federal And Foreign Tax Attributes With Potential Tax Benefits Valuation Allowance FederalAndForeignTaxAttributesWithPotentialTaxBenefitsValuationAllowance	3400000	USD
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CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	49300000	USD
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CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	38100000	USD
CY2020Q4	us-gaap	Stock Repurchase Program Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased	20000000	shares
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	6400000	shares
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	8600000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	8700000	USD
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CY2020Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	20800000	USD
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CY2020Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	602919000	USD
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CY2020Q1	us-gaap	Profit Loss ProfitLoss	33951000	USD
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CY2020Q4	us-gaap	Net Income Loss NetIncomeLoss	36420000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.58
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
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CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.57
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CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.64
CY2020Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
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CY2019Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	611781000	USD
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	666394000	USD
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CY2019Q3	us-gaap	Gross Profit GrossProfit	97814000	USD
CY2019Q4	us-gaap	Gross Profit GrossProfit	94358000	USD
CY2019Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	543839000	USD
CY2019Q1	us-gaap	Gross Profit GrossProfit	100388000	USD
CY2019Q2	us-gaap	Gross Profit GrossProfit	102446000	USD
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CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	29093000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	28170000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.28
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.52
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.28
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CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.52
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.50
CY2019Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
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CY2019Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
CY2019Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10

Files In Submission

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$MLI
MUELLER INDUSTRIES INC Stock $mli

2020 Q4 Form 10-K Financial Statement

#000008943921000015 Filed on February 24, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MLI MUELLER INDUSTRIES INC Stock $mli

2020 Q4 Form 10-K Financial Statement

#000008943921000015 Filed on February 24, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MLI
MUELLER INDUSTRIES INC Stock $mli