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Significant Accounting Policies (Tables) | 3 Months Ended
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Mar. 31, 2025
Significant Accounting Policies [Line Items] |
Consolidated Comprehensive Earnings | Consolidated comprehensive earnings attributable to Martin Marietta are as follows:
|  | Three Months Ended |
|  | March 31, |
|  | 2025 |  |  | 2024 |
|  | (Dollars in Millions) |
Net earnings attributable to Martin Marietta |  | $ | 116 |  |  | $ | 1,045 |
Other comprehensive earnings, net of tax |  |  | 1 |  |  |  | — |
Consolidated comprehensive earnings attributable to Martin Marietta |  | $ | 117 |  |  | $ | 1,045 |
Changes in Accumulated Other Comprehensive Loss Net of Tax | The components of the changes in accumulated other comprehensive loss, net of tax, are as follows:
|  | (Dollars in Millions) |
|  | Pension and Postretirement Benefit Plans |  |  | Foreign Currency |  |  | Accumulated Other Comprehensive Loss |
|  | Three Months Ended March 31, 2025 |
Balance at beginning of period |  | $ | (9 | ) |  | $ | (4 | ) |  | $ | (13 | )
Amounts reclassified from accumulated other comprehensive loss, net of tax |  |  | 1 |  |  |  | — |  |  |  | 1 |
Other comprehensive earnings, net of tax |  |  | 1 |  |  |  | — |  |  |  | 1 |
Balance at end of period |  | $ | (8 | ) |  | $ | (4 | ) |  | $ | (12 | )
|  | Three Months Ended March 31, 2024 |
Balance at beginning of period |  | $ | (48 | ) |  | $ | (1 | ) |  | $ | (49 | )
Other comprehensive loss before reclassifications, net of tax |  |  | — |  |  |  | (1 | ) |  |  | (1 | )
Amounts reclassified from accumulated other comprehensive loss, net of tax |  |  | 1 |  |  |  | — |  |  |  | 1 |
Other comprehensive earnings (loss), net of tax |  |  | 1 |  |  |  | (1 | ) |  |  | — |
Balance at end of period |  | $ | (47 | ) |  | $ | (2 | ) |  | $ | (49 | )
Noncurrent Deferred Tax Assets Recorded in Accumulated Other Comprehensive Loss | Changes in net noncurrent deferred tax assets related to accumulated other comprehensive loss are as follows:
|  | Pension and Postretirement Benefit Plans |
|  | Three Months Ended |
|  | March 31, |
|  | 2025 |  |  | 2024 |
|  | (Dollars in Millions) |
Balance at beginning of period |  | $ | 41 |  |  | $ | 54 |
Tax effect of other comprehensive earnings |  |  | (1 | ) |  |  | (1 | )
Balance at end of period |  | $ | 40 |  |  | $ | 53 |
Reclassification Out of Accumulated Other Comprehensive Loss | Reclassifications out of accumulated other comprehensive loss are as follows:
|  | Three Months Ended |  |  | Affected line items in the consolidated
|  | March 31, |  |  | statements of earnings
|  | 2025 |  |  | 2024 |  |  | and comprehensive earnings
|  | (Dollars in Millions) |
Pension and postretirement benefit plans |  |  |  |  |  |  |  |
Amortization of prior service cost |  | $ | 2 |  |  | $ | 2 |  |  | Other nonoperating income, net
Tax effect |  |  | (1 | ) |  |  | (1 | ) |  | Income tax expense
Total |  | $ | 1 |  |  | $ | 1 |  |  |
Basic and Diluted Earnings from Continuing Operations Per Common Share | The following table reconciles the denominator for basic and diluted earnings per common share:
|  | Three Months Ended |
|  | March 31, |
|  | 2025 |  |  | 2024 |
|  | (In Millions) |
Basic weighted-average common shares outstanding |  |  | 60.9 |  |  |  | 61.8 |
Effect of dilutive employee and director awards |  |  | 0.1 |  |  |  | 0.2 |
Diluted weighted-average common shares outstanding |  |  | 61.0 |  |  |  | 62.0 |

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