Represents the range of period at maturity date, at which individual draws on the JV Credit Agreement , in MM format.

No definition available.

Name:	mli_DebtInstrumentMaturityPeriodRange
Namespace Prefix:	mli_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The initial term of the invoice facility.

+ References

No definition available.

+ Details

Name:	mli_InitialTermOfInvoiceFacility
Namespace Prefix:	mli_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of banks in the credit agreement syndicate.

+ References

No definition available.

+ Details

Name:	mli_NumberOfBanksInCreditAgreementSyndicate
Namespace Prefix:	mli_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt (Details) In Millions, unless otherwise specified	0 Months Ended		9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended
Debt (Details) In Millions, unless otherwise specified	Mar. 21, 2014 Mueller Europe Limited [Member] USD ($)	Mar. 21, 2014 Mueller Europe Limited [Member] GBP (£)	Sep. 27, 2014 Mueller Europe Limited [Member] USD ($)	Sep. 23, 2013 Mueller Xingrong Line of Credit [Member] Bank	Sep. 27, 2014 Mueller Xingrong Line of Credit [Member] USD ($)	Sep. 23, 2013 Mueller Xingrong Line of Credit [Member] Maximum [Member]	Sep. 27, 2014 Revolving Credit Facility [Member]	May 29, 2014 Revolving Credit Facility [Member] USD ($)	Mar. 29, 2014 Revolving Credit Facility [Member] USD ($)	May 29, 2014 Term Loan [Member] USD ($)
Line of Credit Facility [Line Items]
Maturity Date				Sep. 24, 2014			Dec. 11, 2017
Line of credit facility maximum borrowing capacity	$ 65.9	£ 40.0						$ 200.0	$ 350.0	$ 200.0
Initial term of the Invoice Facility	2 years	2 years
Borrowings outstanding			$ 11.7		$ 24.5
Debt instrument variable rate basis			bear interest at the latest base-lending rate published by HSBC plus 155 basis points		bear an interst rate at the latest base-lending rate published by the People’s Bank of China
Basis spread on variable rate (in hundredths)			1.55%
Debt, stated interest rate (in hundredths)			2.05%		5.60%
Number of banks in the credit agreement syndicate				4
Range of period at maturity date						9 months