Consolidated Statements of Earnings and Comprehensive Earnings (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Total Revenues	$ 1,557.3	$ 1,321.4	$ 3,917.6	$ 3,550.3
Total Cost of Revenues	1,115.4	916.9	2,915.9	2,622.9
Gross Profit	441.9	404.5	1,001.7	927.4
Selling, general & administrative expenses	86.0	71.1	248.2	221.0
Acquisition-related expenses	7.4	0.4	18.0	1.2
Other operating income, net	(8.4)	(67.6)	(28.2)	(59.6)
Earnings from Operations	356.9	400.6	763.7	764.8
Interest expense	44.3	28.7	99.9	89.7
Other nonoperating income, net	(5.6)	(4.0)	(23.8)	(5.9)
Earnings before income tax expense	318.2	375.9	687.6	681.0
Income tax expense	63.6	81.5	141.7	143.0
Consolidated net earnings	254.6	294.4	545.9	538.0
Less: Net earnings attributable to noncontrolling interests			0.2
Net Earnings Attributable to Martin Marietta Materials, Inc.	254.6	294.4	545.7	538.0
Consolidated Comprehensive Earnings:
Earnings attributable to Martin Marietta Materials, Inc.	256.2	298.0	552.7	545.2
Earnings attributable to noncontrolling interests			0.2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 256.2	$ 298.0	$ 552.9	$ 545.2
Net Earnings Attributable to Martin Marietta Materials, Inc. Per Common Share:
Basic attributable to common shareholders	$ 4.08	$ 4.72	$ 8.74	$ 8.63
Diluted attributable to common shareholders	$ 4.07	$ 4.71	$ 8.72	$ 8.61
Weighted-Average Common Shares Outstanding:
Basic	62.4	62.3	62.4	62.3
Diluted	62.6	62.4	62.6	62.4
Products and Services
Total Revenues	$ 1,462.7	$ 1,240.7	$ 3,679.9	$ 3,321.2
Total Cost of Revenues	1,021.0	836.1	2,676.9	2,390.9
Freight
Total Revenues	94.6	80.7	237.7	229.1
Total Cost of Revenues	$ 94.4	$ 80.8	$ 239.0	$ 232.0