Significant Accounting Policies - Comprehensive Earnings Attributable to Martin Marietta Materials Incorporated (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 363	$ 417	$ 1,701	$ 886
Other comprehensive earnings, net of tax	2	0	3	3
Earnings attributable to Martin Marietta	$ 365	$ 417	$ 1,704	$ 889