Significant Accounting Policies - Noncurrent Deferred Tax Assets Recorded in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Equity [Abstract]
Balance at beginning of period	$ 50.1	$ 69.7
Tax effect of other comprehensive (earnings) loss	(0.3)	10.5
Balance at end of period	$ 49.8	$ 80.2

Accumulated other comprehensive loss, noncurrent deferred tax assets, other comprehensive earnings, tax effect, pension and postretirement benefit plans.

No definition available.

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