XML 78 R66.htm IDEA: XBRL DOCUMENT
v3.21.2

Other Operating Income, Net - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Component of Other Operating Income and Expense [Line Items] |  |  |
Gains on sales of investment |  | $ 26.6 | $ 71.2
Former Corporate Headquarters | Other Operating Income, Net |  |  |
Component of Other Operating Income and Expense [Line Items] |  |  |
Gains on sales of investment |  | $ 12.3 |
Land and Divested Assets | Other Operating Income, Net | West Group |  |  |
Component of Other Operating Income and Expense [Line Items] |  |  |
Gains on sales of investment | $ 69.9 |  | $ 69.9

X
- Definition Component of other operating income and expense. + References No definition available. + Details
Name: | mlm_ComponentOfOtherOperatingIncomeAndExpenseLineItems
Namespace Prefix: | mlm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=123351718&loc=d3e2443-110228 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230 + Details
Name: | us-gaap_GainLossOnDispositionOfAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=mlm_FormerCorporateHeadquartersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherOperatingIncomeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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