Adjusted earnings before interest tax depreciation and amortization.

No definition available.

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Namespace Prefix:	mlm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount by which consolidated debt, for purposes of calculating the debt covenant ratio, may be reduced for unrestricted cash and cash equivalents, provided no amounts are outstanding under the revolving credit facility and the AR credit facility.

+ References

No definition available.

+ Details

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

- Definition

Debt instrument maturity date year.

+ References

No definition available.

+ Details

Name:	mlm_DebtInstrumentMaturityDateYear
Namespace Prefix:	mlm_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Eligible trade receivables.

+ References

No definition available.

+ Details

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

- Definition

Increase in annual interest expense due to ongoing amortization of the terminated value of the Swap agreements.

+ References

No definition available.

+ Details

Name:	mlm_IncreaseInAnnualInterestExpenseDueToOngoingAmortizationOfTerminatedValueOfSwapAgreements
Namespace Prefix:	mlm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of credit facility borrowing base.

+ References

No definition available.

+ Details

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

- Definition

Maximum consolidated debt reduction for unrestricted cash and cash equivalents for debt covenant calculation.

+ References

No definition available.

+ Details

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

- Definition

Term loan credit facility commitment.

+ References

No definition available.

+ Details

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

- Definition

Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessCombinationIntegrationRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

+ 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 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentCovenantDescription
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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

The amount of net gains or losses on interest rate cash flow hedges reclassified during the period to earnings from accumulated other comprehensive income upon the hedged transaction affecting earnings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

+ Details

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

- 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

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

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mlm_TexasIndustriesIncMember
Namespace Prefix:
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Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=mlm_ExcludingAcquisitionBridgeDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mlm_IncludingAcquisitionBridgeDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=mlm_TradeReceivableCreditFacilityMember
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Data Type:	na
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Period Type:

- Details

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Long-Term Debt - Additional information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Debt Instrument [Line Items]
Term loan facility commitment	$ 250,000,000mlm_TermLoanCreditFacilityCommitment
Maximum consolidated debt reduction for unrestricted cash and cash equivalents for debt covenant calculation	200,000,000
Additional interest expense	307,000	288,000
6.6% Senior Notes, Due 2018
Debt Instrument [Line Items]
Interest rate on notes	6.60%
Maturity date	2018
Increase in annual interest expense due to ongoing amortization of the terminated value of the swap agreements	1,200,000
Texas Industries Inc.
Debt Instrument [Line Items]
Acquisition integration expenses	1,451,000
Texas Industries Inc. \| 9.25% Senior Notes due 2020
Debt Instrument [Line Items]
Interest rate on notes			9.25%
Maturity date			2020
Minimum
Debt Instrument [Line Items]
Reduction of consolidated debt in the debt ratio calculation	50,000,000
Maximum \| Texas Industries Inc.
Debt Instrument [Line Items]
Amendment consolidated EBITDA			95,000,000
Acquisition integration expenses			70,000,000
Including Acquisition Bridge Debt
Debt Instrument [Line Items]
Debt covenant	3.50x
Excluding Acquisition Bridge Debt
Debt Instrument [Line Items]
Debt covenant	3.75x
Revolving Facility
Debt Instrument [Line Items]
Credit facility commitment	350,000,000
Senior unsecured revolving facility, maturity period	5 years
Outstanding letters of credit	2,507,000	2,507,000	2,507,000
Trade Receivable Facility
Debt Instrument [Line Items]
Credit facility commitment	250,000,000
Debt instrument maturity period	Sep. 30, 2016
Eligible trade receivables	339,086,000	232,566,000	369,575,000
Credit facility borrowing base	$ 280,101,000	$ 177,233,000	313,428,000
London Interbank Offered Rate(LIBOR) \| Trade Receivable Facility
Debt Instrument [Line Items]
Basis spread on variable rate	0.70%