XML 36 R24.htm IDEA: XBRL DOCUMENT
v3.21.1

Revenue Recognition (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2021
Revenue From Contract With Customer [Abstract] |
Schedule of Company's Total Revenues by Category for each Reportable Segment | The following table presents the Company’s total revenues by category for each reportable segment.
|  | Three Months Ended |
|  | March 31, 2021 |
|  | Products and Services |  |  | Freight |  |  | Total |
|  | (Dollars in Millions) |
East Group |  | $ | 372.5 |  |  | $ | 22.4 |  |  | $ | 394.9 |
West Group |  |  | 484.1 |  |  |  | 32.5 |  |  |  | 516.6 |
Total Building Materials business |  |  | 856.6 |  |  |  | 54.9 |  |  |  | 911.5 |
Magnesia Specialties |  |  | 65.3 |  |  |  | 5.6 |  |  |  | 70.9 |
Total |  | $ | 921.9 |  |  | $ | 60.5 |  |  | $ | 982.4 |
|  | Three Months Ended |
|  | March 31, 2020 |
|  | Products and Services |  |  | Freight |  |  | Total |
|  | (Dollars in Millions) |
East Group |  | $ | 357.9 |  |  | $ | 24.0 |  |  | $ | 381.9 |
West Group |  |  | 473.2 |  |  |  | 37.4 |  |  |  | 510.6 |
Total Building Materials business |  |  | 831.1 |  |  |  | 61.4 |  |  |  | 892.5 |
Magnesia Specialties |  |  | 59.9 |  |  |  | 5.8 |  |  |  | 65.7 |
Total |  | $ | 891.0 |  |  | $ | 67.2 |  |  | $ | 958.2 |
Summary of Information About the Company's Contract Balances | The following table presents information about the Company’s contract balances:
(Dollars in Millions) |  | March 31, 2021 |  |  | December 31, 2020 |
Costs in excess of billings |  | $ | 1.4 |  |  | $ | 2.2 |
Billings in excess of costs |  | $ | 11.6 |  |  | $ | 14.0 |

X
- Definition Schedule of revenue by category for reportable segment. + References No definition available. + Details
Name: | mlm_ScheduleOfRevenueByCategoryForReportableSegmentTableTextBlock
Namespace Prefix: | mlm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of receivable, contract asset, and contract liability from contract with customer. Includes, but is not limited to, change in contract asset and contract liability. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045 + Details
Name: | us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RevenueFromContractWithCustomerAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration