Consolidated Statements of Earnings and Comprehensive Earnings (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Total Revenues	$ 1,219,640	$ 1,087,732	$ 3,224,047	$ 2,995,116
Total Cost of Revenues	906,656	796,054	2,484,754	2,282,278
Gross Profit	312,984	291,678	739,293	712,838
Selling, general & administrative expenses	68,441	57,219	209,632	195,127
Acquisition-related expenses, net	89	1,314	12,925	3,319
Other operating expenses (income), net	3,792	6,181	(26,960)	(2,575)
Earnings from Operations	240,662	226,964	543,696	516,967
Interest expense	35,468	23,141	103,526	68,037
Other nonoperating income, net	(4,248)	(479)	(19,873)	(6,434)
Earnings before income tax expense	209,442	204,302	460,043	455,364
Income tax expense	29,089	52,763	84,147	119,277
Consolidated net earnings	180,353	151,539	375,896	336,087
Less: Net earnings (loss) attributable to noncontrolling interests	132	(7)	275	(72)
Net Earnings Attributable to Martin Marietta Materials, Inc.	180,221	151,546	375,621	336,159
Consolidated Comprehensive Earnings: (See Note 1)
Earnings attributable to Martin Marietta Materials, Inc.	184,613	154,524	383,234	343,918
Earnings (Loss) attributable to noncontrolling interests	132	1	276	(62)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 184,745	$ 154,525	$ 383,510	$ 343,856
Net Earnings Attributable to Martin Marietta Materials, Inc. Per Common Share:
Basic attributable to common shareholders	$ 2.86	$ 2.40	$ 5.95	$ 5.33
Diluted attributable to common shareholders	$ 2.85	$ 2.39	$ 5.93	$ 5.30
Weighted-Average Common Shares Outstanding:
Basic	62,932	62,896	62,970	62,940
Diluted	63,167	63,158	63,224	63,218
Cash Dividends Per Common Share	$ 0.48	$ 0.44	$ 1.36	$ 1.28
Products and Services
Total Revenues	$ 1,142,218	$ 1,022,487	$ 3,024,300	$ 2,811,646
Total Cost of Revenues	828,110	730,459	2,282,159	2,097,272
Freight
Total Revenues	77,422	65,245	199,747	183,470
Total Cost of Revenues	$ 78,546	$ 65,595	$ 202,595	$ 185,006