Consolidated Statements of Earnings - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total revenues	$ 4,729.9	$ 4,739.1	$ 4,244.3
Total cost of revenues	3,477.1	3,560.1	3,277.7
Gross Profit	1,252.8	1,179.0	966.6
Selling, general and administrative expenses	305.9	302.7	280.6
Acquisition-related expenses, net	1.3	0.5	13.5
Other operating income, net	(59.8)	(9.1)	(18.2)
Earnings from Operations	1,005.4	884.9	690.7
Interest expense	118.1	129.3	137.1
Other nonoperating (income) and expenses, net	(2.0)	7.3	(22.5)
Earnings before income tax expense	889.3	748.3	576.1
Income tax expense	168.2	136.3	105.7
Consolidated net earnings	721.1	612.0	470.4
Less: Net earnings attributable to noncontrolling interests	0.1	0.1	0.4
Net Earnings Attributable to Martin Marietta	$ 721.0	$ 611.9	$ 470.0
Net Earnings Attributable to Martin Marietta Per Common Share (see Note A)
Basic attributable to common shareholders	$ 11.56	$ 9.77	$ 7.46
Diluted attributable to common shareholders	$ 11.54	$ 9.74	$ 7.43
Weighted-Average Common Shares Outstanding
Basic	62.3	62.5	62.9
Diluted	62.4	62.7	63.1
Products and Services
Total revenues	$ 4,432.1	$ 4,422.3	$ 3,980.4
Total cost of revenues	3,175.6	3,239.1	3,009.8
Freight
Total revenues	297.8	316.8	263.9
Total cost of revenues	$ 301.5	$ 321.0	$ 267.9