Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2017

Significant Accounting Policies [Line Items]

Changes in Accumulated Other Comprehensive Earnings (Loss), Net of Tax

Changes in accumulated other comprehensive earnings (loss), net of tax, are as follows:  

	(Dollars in Thousands)
							Unamortized
							Value of
							Terminated			Accumulated
	Pension and						Forward Starting			Other
	Postretirement			Foreign			Interest Rate			Comprehensive
	Benefit Plans			Currency			Swap			Loss
	Three Months Ended June 30, 2017
Balance at beginning of period	$	(126,463	)	$	(1,025	)	$	(937	)	$	(128,425	)
Other comprehensive earnings before reclassifications,    net of tax		—			389			—			389
Amounts reclassified from accumulated other    comprehensive earnings, net of tax		1,910			—			220			2,130
Other comprehensive earnings, net of tax		1,910			389			220			2,519
Balance at end of period	$	(124,553	)	$	(636	)	$	(717	)	$	(125,906	)
	Three Months Ended June 30, 2016
Balance at beginning of period	$	(101,907	)	$	(149	)	$	(1,777	)	$	(103,833	)
Other comprehensive loss before reclassifications,    net of tax		(3,736	)		(232	)		—			(3,968	)
Amounts reclassified from accumulated other    comprehensive earnings, net of tax		1,529			—			204			1,733
Other comprehensive (loss) earnings, net of tax		(2,207	)		(232	)		204			(2,235	)
Balance at end of period	$	(104,114	)	$	(381	)	$	(1,573	)	$	(106,068	)

1. Significant Accounting Policies (continued)

Consolidated Comprehensive Earnings/Loss and Accumulated Other Comprehensive Loss (continued)

	(Dollars in Thousands)
							Unamortized
							Value of
							Terminated			Accumulated
	Pension and						Forward Starting			Other
	Postretirement			Foreign			Interest Rate			Comprehensive
	Benefit Plans			Currency			Swap			Loss
	Six Months Ended June 30, 2017
Balance at beginning of period	$	(128,373	)	$	(1,162	)	$	(1,152	)	$	(130,687	)
Other comprehensive earnings before reclassifications,    net of tax		—			526			—			526
Amounts reclassified from accumulated other    comprehensive earnings, net of tax		3,820			—			435			4,255
Other comprehensive earnings, net of tax		3,820			526			435			4,781
Balance at end of period	$	(124,553	)	$	(636	)	$	(717	)	$	(125,906	)
	Six Months Ended June 30, 2016
Balance at beginning of period	$	(103,380	)	$	(264	)	$	(1,978	)	$	(105,622	)
Other comprehensive loss before reclassifications,    net of tax		(3,830	)		(117	)		—			(3,947	)
Amounts reclassified from accumulated other    comprehensive earnings, net of tax		3,096			—			405			3,501
Other comprehensive (loss) earnings, net of tax		(734	)		(117	)		405			(446	)
Balance at end of period	$	(104,114	)	$	(381	)	$	(1,573	)	$	(106,068	)

Noncurrent Deferred Tax Assets Recorded In Accumulated Other Comprehensive Loss

Changes in net noncurrent deferred tax assets recorded in accumulated other comprehensive loss are as follows:

	(Dollars in Thousands)
	Pension and Postretirement Benefit Plans			Unamortized Value of Terminated Forward Starting Interest Rate Swap			Net Noncurrent Deferred Tax Assets
	Three Months Ended June 30, 2017
Balance at beginning of period	$	80,859		$	608		$	81,467
Tax effect of other comprehensive earnings		(1,184	)		(144	)		(1,328	)
Balance at end of period	$	79,675		$	464		$	80,139
	Three Months Ended June 30, 2016
Balance at beginning of period	$	65,523		$	1,159		$	66,682
Tax effect of other comprehensive earnings		1,408			(136	)		1,272
Balance at end of period	$	66,931		$	1,023		$	67,954
	Six Months Ended June 30, 2017
Balance at beginning of period	$	82,044		$	749		$	82,793
Tax effect of other comprehensive earnings		(2,369	)		(285	)		(2,654	)
Balance at end of period	$	79,675		$	464		$	80,139
	Six Months Ended June 30, 2016
Balance at beginning of period	$	66,467		$	1,290		$	67,757
Tax effect of other comprehensive earnings		464			(267	)		197
Balance at end of period	$	66,931		$	1,023		$	67,954

Reclassification Out of Accumulated Other Comprehensive Loss

1. Significant Accounting Policies (continued)

Consolidated Comprehensive Earnings/Loss and Accumulated Other Comprehensive Loss (continued)

Reclassifications out of accumulated other comprehensive loss are as follows:

	Three Months Ended						Six Months Ended						Affected line items in the consolidated
	June 30,						June 30,						statements of earnings and
	2017			2016			2017			2016			comprehensive earnings
	(Dollars in Thousands)
Pension and postretirement    benefit plans
Settlement charge	$	—		$	—		$	—		$	59
Amortization of:
Prior service credit		(358	)		(518	)		(716	)		(806	)
Actuarial loss		3,452			3,007			6,905			5,787
		3,094			2,489			6,189			5,040		Nonoperating expenses
Tax benefit		(1,184	)		(960	)		(2,369	)		(1,944	)	Taxes on income
	$	1,910		$	1,529		$	3,820		$	3,096
Unamortized value of terminated    forward starting interest    rate swap
Additional interest expense	$	364		$	340		$	720		$	672		Interest expense
Tax benefit		(144	)		(136	)		(285	)		(267	)	Taxes on income
	$	220		$	204		$	435		$	405

Basic and Diluted Earnings Per Common Share

1. Significant Accounting Policies (continued)

Earnings per Common Share

The following table reconciles the numerator and denominator for basic and diluted earnings per common share:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
	(In Thousands)
Net earnings attributable to Martin Marietta    Materials, Inc.	$	142,279	$	122,052	$	184,613	$	167,047
Less: Distributed and undistributed earnings    attributable to unvested awards		413		519		553		730
Basic and diluted net earnings available to common    shareholders attributable to Martin Marietta    Materials, Inc.	$	141,866	$	121,533	$	184,060	$	166,317
Basic weighted-average common shares outstanding		62,858		63,532		62,961		63,845
Effect of dilutive employee and director awards		283		270		285		246
Diluted weighted-average common shares outstanding		63,141		63,802		63,246		64,091

Parent

Significant Accounting Policies [Line Items]

Comprehensive Earnings

Comprehensive earnings attributable to Martin Marietta is as follows:

	Three Months Ended					Six Months Ended
	June 30,					June 30,
	2017		2016			2017		2016
	(Dollars in Thousands)
Net earnings attributable to Martin Marietta Materials, Inc.	$	142,279	$	122,052		$	184,613	$	167,047
Other comprehensive earnings (loss), net of tax		2,519		(2,235	)		4,781		(446	)
Comprehensive earnings attributable to Martin Marietta    Materials, Inc.	$	144,798	$	119,817		$	189,394	$	166,601

Noncontrolling Interests

Significant Accounting Policies [Line Items]

Comprehensive Earnings

Comprehensive earnings attributable to noncontrolling interests, consisting of net earnings and adjustments for the funded status of pension and postretirement benefit plans, is as follows:

	Three Months Ended					Six Months Ended
	June 30,					June 30,
	2017			2016		2017			2016
	(Dollars in Thousands)
Net (loss) earnings attributable to noncontrolling interests	$	(38	)	$	61	$	(65	)	$	122
Other comprehensive earnings, net of tax		1			2		2			33
Comprehensive (loss) earnings attributable to    noncontrolling interests	$	(37	)	$	63	$	(63	)	$	155