Income Taxes - Additional Information (Detail)	3 Months Ended
Mar. 31, 2015
Income Tax Disclosure [Abstract]
Estimated effective income tax rate, excluding discrete items	31.00%

Estimated effective income tax rate, excluding discrete items.

No definition available.

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