Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2012

Significant Accounting Policies [Abstract]

Changes In Accumulated Other Comprehensive Loss, Net Of Tax

	Three Months Ended March 31, 2012
	(Dollars in Thousands)
	Pension and   Postretirement   Benefit Plans		Foreign Currency		Unamortized Value of Terminated Forward Starting Interest Rate Swap		Accumulated Other Comprehensive Loss
Balance at beginning of period	$	(84,204)	$	5,076	$	(4,762)	$	(83,890)
Other comprehensive earnings, net of tax		1,548		199		152		1,899
Balance at end of period	$	(82,656)	$	5,275	$	(4,610)	$	(81,991)

Noncurrent Deferred Tax Assets Recorded In Accumulated Other Comprehensive Loss

	Three Months Ended March 31, 2012
	(Dollars in Thousands)
	Pension and   Postretirement   Benefit Plans		Unamortized Value of Terminated Forward Starting Interest Rate Swap		Net Noncurrent Deferred Tax Assets
Balance at beginning of period	$	55,161	$	3,116	$	58,277
Other comprehensive earnings, tax effect		(1,013)		(99)		(1,112)
Balance at end of period	$	54,148	$	3,017	$	57,165

Basic And Diluted Earnings (Loss) Per Common Share

	Three Months Ended March  31,
	2012		2011
	(In Thousands)
Net loss from continuing operations attributable to Martin Marietta Materials, Inc.	$	(36,140)	$	(15,958)
Less: Distributed and undistributed earnings attributable to unvested awards		(126)		(165)
Basic and diluted net loss available to common shareholders from continuing operations attributable to Martin Marietta Materials, Inc.		(36,266)		(16,123)
Basic and diluted net loss available to common shareholders from discontinued operations		(592)		(1,456)
Basic and diluted net loss available to common shareholders attributable to Martin Marietta Materials, Inc.	$	(36,858)	$	(17,579)
Basic weighted-average common shares outstanding		45,734		45,584
Effect of dilutive employee and director awards		--		--
Diluted weighted-average common shares outstanding		45,734		45,584