Consolidated Statements of Earnings and Comprehensive Earnings (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net Sales	$ 996,289	$ 915,436	$ 1,787,973	$ 1,649,396
Freight and delivery revenues	67,235	61,862	119,410	116,636
Total revenues	1,063,524	977,298	1,907,383	1,766,032
Cost of sales	722,195	668,005	1,366,813	1,256,715
Freight and delivery costs	67,235	61,862	119,410	116,636
Total cost of revenues	789,430	729,867	1,486,223	1,373,351
Gross Profit	274,094	247,431	421,160	392,681
Selling, general & administrative expenses	68,373	59,781	137,908	118,130
Acquisition-related expenses, net	1,982	248	2,004	547
Other operating income, net	(9,113)	(3,446)	(8,754)	(2,868)
Earnings from Operations	212,852	190,848	290,002	276,872
Interest expense	24,045	20,294	44,896	40,328
Other nonoperating income, net	(5,420)	(4,994)	(5,956)	(3,770)
Earnings before taxes on income	194,227	175,548	251,062	240,314
Taxes on income	51,986	53,435	66,514	73,145
Consolidated net earnings	142,241	122,113	184,548	167,169
Less: Net (loss) earnings attributable to noncontrolling interests	(38)	61	(65)	122
Net Earnings Attributable to Martin Marietta Materials, Inc.	142,279	122,052	184,613	167,047
Consolidated Comprehensive Earnings: (See Note 1)
Earnings attributable to Martin Marietta Materials, Inc.	144,798	119,817	189,394	166,601
(Loss) Earnings attributable to noncontrolling interests	(37)	63	(63)	155
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 144,761	$ 119,880	$ 189,331	$ 166,756
Net Earnings Attributable to Martin Marietta Materials, Inc. Per Common Share:
Basic attributable to common shareholders	$ 2.26	$ 1.91	$ 2.92	$ 2.61
Diluted attributable to common shareholders	$ 2.25	$ 1.90	$ 2.91	$ 2.60
Weighted-Average Common Shares Outstanding:
Basic	62,858	63,532	62,961	63,845
Diluted	63,141	63,802	63,246	64,091
Cash Dividends Per Common Share	$ 0.42	$ 0.40	$ 0.84	$ 0.80