XML 78 R60.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Goodwill and Other Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 29, 2018 | Dec. 30, 2017 | Dec. 31, 2016
Goodwill [Roll Forward] |  |  |
Goodwill |  | $ 173,398,000 |
Accumulated impairment charges, beginning of year |  | (49,405,000) |
Goodwill, net, beginning balance | $ 130,293,000 | 123,993,000 |
Additions | 22,819,000 | 3,852,000 |
Currency translation | (2,777,000) | 2,448,000 |
Goodwill | 199,740,000 |  | $ 173,398,000
Accumulated impairment loss, end of year | (49,405,000) |  | (49,405,000)
Goodwill, net, ending balance | 150,335,000 | 130,293,000 | 123,993,000
Impairment charges | 0 | 0 | 0
Jungwoo-Mueller [Member] |  |  |
Goodwill [Roll Forward] |  |  |
Purchase price allocation adjustments | (200,000) |  |
Heatlink Group [Member] |  |  |
Goodwill [Roll Forward] |  |  |
Purchase price allocation adjustments | 2,800,000 |  |
Piping Systems [Member] |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill |  | 160,128,000 |
Accumulated impairment charges, beginning of year |  | (40,552,000) |
Goodwill, net, beginning balance | 125,876,000 | 119,576,000 |
Additions | 5,049,000 | 3,852,000 |
Currency translation | (2,777,000) | 2,448,000 |
Goodwill | 168,700,000 |  | 160,128,000
Accumulated impairment loss, end of year | (40,552,000) |  | (40,552,000)
Goodwill, net, ending balance | 128,148,000 | 125,876,000 | 119,576,000
Industrial Metals [Member] |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill |  | 8,854,000 |
Accumulated impairment charges, beginning of year |  | (8,853,000) |
Goodwill, net, beginning balance | 1,000 | 1,000 |
Additions | 0 | 0 |
Currency translation | 0 | 0 |
Goodwill | 8,854,000 |  | 8,854,000
Accumulated impairment loss, end of year | (8,853,000) |  | (8,853,000)
Goodwill, net, ending balance | 1,000 | 1,000 | 1,000
Climate [Member] |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill |  | 4,416,000 |
Accumulated impairment charges, beginning of year |  | 0 |
Goodwill, net, beginning balance | 4,416,000 | 4,416,000 |
Additions | 17,770,000 | 0 |
Currency translation | 0 | 0 |
Goodwill | 22,186,000 |  | 4,416,000
Accumulated impairment loss, end of year | 0 |  | 0
Goodwill, net, ending balance | $ 22,186,000 | $ 4,416,000 | $ 4,416,000

X
- Definition A revision in the estimates made in the allocation of the costs of an acquisition to the individual or groups of acquired assets, liabilities, in-process research and development, and goodwill. + References No definition available. + Details
Name: | mli_PurchasePriceAllocationAdjustments
Namespace Prefix: | mli_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillForeignCurrencyTranslationGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillImpairedAccumulatedImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13854-109267 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13777-109266 + Details
Name: | us-gaap_GoodwillImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_GoodwillRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mli_JungwooMuellerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mli_HeatlinkGroupMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mli_PipingSystemsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mli_IndustrialMetalsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mli_ClimateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |