Comprehensive Earnings Attributable to Martin Marietta Materials Inc (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Comprehensive Income (Loss)
Net earnings attributable to Martin Marietta Materials, Inc.	$ 62,922	$ 49,156	$ 62,940	$ 67,541
Other comprehensive earnings (loss), net of tax	3,160	(240)	6,410	4,100
Consolidated comprehensive earnings attributable to Martin Marietta Materials, Inc.	$ 66,082	$ 48,916	$ 69,350	$ 71,641

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

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