Consolidated Statements of Earnings and Comprehensive Earnings (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Products and services revenues	$ 753,305	$ 792,316
Freight revenues	48,699	51,543
Total Revenues	802,004	843,859
Cost of revenues - products and services	641,620	644,617
Cost of revenues - freight	49,992	52,175
Total Cost of Revenues	691,612	696,792
Gross Profit	110,392	147,067
Selling, general & administrative expenses	70,121	69,535
Acquisition-related expenses	711	22
Other operating expense, net	479	360
Earnings from Operations	39,081	77,150
Interest expense	35,087	20,851
Other nonoperating income, net	(8,503)	(536)
Earnings before income tax expense	12,497	56,835
Income tax expense	2,457	14,528
Consolidated net earnings	10,040	42,307
Less: Net earnings (loss) attributable to noncontrolling interests	17	(27)
Net Earnings Attributable to Martin Marietta Materials, Inc.	10,023	42,334
Consolidated Comprehensive Earnings: (See Note 1)
Earnings attributable to Martin Marietta Materials, Inc.	11,642	44,596
Earnings (Loss) attributable to noncontrolling interests	17	(26)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 11,659	$ 44,570
Net Earnings Attributable to Martin Marietta Materials, Inc. Per Common Share:
Basic attributable to common shareholders	$ 0.16	$ 0.67
Diluted attributable to common shareholders	$ 0.16	$ 0.67
Weighted-Average Common Shares Outstanding:
Basic	62,957	63,024
Diluted	63,222	63,319
Cash Dividends Per Common Share	$ 0.44	$ 0.42