Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net Sales	$ 850,249	$ 601,937	$ 1,482,124	$ 981,615
Freight and delivery revenues	71,170	67,288	130,641	116,240
Total revenues	921,419	669,225	1,612,765	1,097,855
Cost of sales	650,096	466,335	1,207,710	820,177
Freight and delivery costs	71,170	67,288	130,641	116,240
Total cost of revenues	721,266	533,623	1,338,351	936,417
Gross Profit	200,153	135,602	274,414	161,438
Selling, general & administrative expenses	56,783	36,566	106,233	70,813
Acquisition-related expenses, net	2,092	5,280	3,696	15,060
Other operating expenses and (income), net	4,294	(2,485)	1,930	(4,779)
Earnings from Operations	136,984	96,241	162,555	80,344
Interest expense	19,087	12,947	38,418	25,149
Other nonoperating (income) and expenses, net	(3,011)	(292)	(2,118)	3,171
Earnings from continuing operations before taxes on income	120,908	83,586	126,255	52,024
Income tax expense	38,929	23,906	38,117	15,482
Earnings from Continuing Operations	81,979	59,680	88,138	36,542
Loss on discontinued operations, net of related tax benefit of $24 and $25, respectively		(56)		(70)
Consolidated net earnings	81,979	59,624	88,138	36,472
Less: Net earnings (loss) attributable to noncontrolling interests	(41)	(103)	(73)	1,432
Net Earnings Attributable to Martin Marietta Materials, Inc.	81,938	59,521	88,065	37,904
Net Earnings (Loss) Attributable to Martin Marietta Materials, Inc.:
Earnings from continuing operations	81,938	59,577	88,065	37,974
Loss from discontinued operations		(56)		(70)
Net Earnings Attributable to Martin Marietta Materials, Inc.	81,938	59,521	88,065	37,904
Consolidated Comprehensive Earnings: (See Note 1)
Earnings attributable to Martin Marietta Materials, Inc.	75,847	60,124	81,410	39,877
Earnings (Loss) attributable to noncontrolling interests	43	104	78	(1,430)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 75,890	$ 60,228	$ 81,488	$ 38,447
Net Earnings (Loss) Attributable to Martin Marietta Materials, Inc. per common share
Basic from continuing operations attributable to common shareholders	$ 1.23	$ 1.28	$ 1.30	$ 0.81
Earnings Per Share, Basic, Total	1.23	1.28	1.30	0.81
Diluted from continuing operations attributable to common shareholders	1.22	1.27	1.30	0.81
Earnings Per Share, Diluted, Total	$ 1.22	$ 1.27	$ 1.30	$ 0.81
Weighted-Average Common Shares Outstanding:
Basic	67,373	46,395	67,392	46,355
Diluted	67,633	46,529	67,654	46,477
Cash Dividends Per Common Share	$ 0.40	$ 0.40	$ 0.80	$ 0.80