Affiliate line of credit facility maturity period.

No definition available.

Name:	mlm_AffiliateLineOfCreditFacilityMaturityPeriod
Namespace Prefix:	mlm_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Asset retirement obligation depreciation and accretion.

+ References

No definition available.

+ Details

Name:	mlm_AssetRetirementObligationDepreciationAndAccretion
Namespace Prefix:	mlm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Balance of top five surety bonds.

+ References

No definition available.

+ Details

Name:	mlm_BalanceOfTop5SuretyBonds
Namespace Prefix:	mlm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	mlm_CommitmentsAndContingenciesLineItems
Namespace Prefix:	mlm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Group of bonds, amount.

+ References

No definition available.

+ Details

Name:	mlm_GroupOfBondsAmount
Namespace Prefix:	mlm_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loan maturity date month and year.

+ References

No definition available.

+ Details

Name:	mlm_LoanMaturityDateMonthAndYear
Namespace Prefix:	mlm_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employees represented in labor union.

+ References

No definition available.

+ Details

Name:	mlm_PercentageOfEmployeesRepresentedInLaborUnion
Namespace Prefix:	mlm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Surety bonds.

+ References

No definition available.

+ Details

Name:	mlm_SuretyBonds
Namespace Prefix:	mlm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Top five surety bonds percentage.

+ References

No definition available.

+ Details

Name:	mlm_Top5SuretyBondsPercentage
Namespace Prefix:	mlm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and due beyond one year (or beyond one operating cycle if longer) to insurance entities to mitigate potential loss from various risks or to satisfy a promise to provide certain coverages to employees.

+ 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 210.5-02.24)

-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 24

-Article 5

+ Details

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

- Definition

For an unclassified balance sheet, amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(k)(1))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph k

-Subparagraph 1

-Article 4

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 3

-Article 7

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.3)

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

+ Details

Name:	us-gaap_DueFromAffiliates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow from advancing money to an affiliate (an entity that is related but not strictly controlled by the entity).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsForAdvanceToAffiliate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireProductiveAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25336-109308

+ Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=mlm_InterestOnlyNoteDueDecemberTwentyNineTwoThousandAndSixteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=mlm_LoanDueMayTwoThousandSixteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=mlm_RevolvingLineOfCreditExpiresInAugustTwoThousandFifteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=mlm_RevolvingLineOfCreditExpiresInJulyTwoThousandThirteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=mlm_CementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=mlm_MagnesiaSpecialtiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=mlm_EnergyAndServiceContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchasedAxis=us-gaap_CapitalAdditionsMember
Namespace Prefix:
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Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 Bond	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies [Line Items]
Asset retirement obligation depreciation and accretion	$ 4,584,000	$ 3,793,000	$ 3,743,000
Liability reserve for insurance claims	42,552,000us-gaap_AccruedInsuranceNoncurrent	25,529,000us-gaap_AccruedInsuranceNoncurrent
Outstanding letters of credit	46,485,000
Surety bonds	305,237,000mlm_SuretyBonds
Balance of top 5 surety bonds	87,283,000mlm_BalanceOfTop5SuretyBonds
Group of bonds, amount	5mlm_GroupOfBondsAmount
Percentage of top 5 surety bonds	29.00%mlm_Top5SuretyBondsPercentage
Loan to affiliate		3,402,000us-gaap_PaymentsForAdvanceToAffiliate	2,000,000us-gaap_PaymentsForAdvanceToAffiliate
Purchase commitments for property, plant and equipment	220,542,000
Capital expenditures	34,135,000	15,839,000	33,654,000
Percentage of employees represented in labor union	13.00%
Magnesia Specialty Products
Commitments and Contingencies [Line Items]
Percentage of employees represented in labor union	100.00%
Cement
Commitments and Contingencies [Line Items]
Percentage of employees represented in labor union	100.00%
Capital Addition Purchase Commitments
Commitments and Contingencies [Line Items]
Purchase commitments for property, plant and equipment	116,681,000
Energy And Service Contracts
Commitments and Contingencies [Line Items]
Purchase commitments for property, plant and equipment	103,861,000
Revolving Line Of Credit Expires In July 2013
Commitments and Contingencies [Line Items]
Guarantee of affiliate's obligations	25,000,000
Revolving Line Of Credit Expires In August 2015
Commitments and Contingencies [Line Items]
Line of credit maturity period	2015-12
Loan Due May 2016
Commitments and Contingencies [Line Items]
Loan to affiliate		3,402,000
Loan to affiliate, due date	2016-05
Due from affiliate	1,808,000
Interest-Only Note Due December 29, 2016
Commitments and Contingencies [Line Items]
Due from affiliate	6,000,000
Revolving Credit Facility
Commitments and Contingencies [Line Items]
Outstanding letters of credit	$ 2,507,000	$ 2,507,000