Comprehensive Earnings Attributable to Martin Marietta Materials Incorporated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Comprehensive Income (Loss)
Net earnings attributable to Martin Marietta Materials, Inc.	$ 71,836	$ 62,922	$ 85,304	$ 62,940
Other comprehensive earnings, net of tax	3,548	3,160	3,459	6,410
Comprehensive earnings attributable to Martin Marietta Materials, Inc.	$ 75,384	$ 66,082	$ 88,763	$ 69,350