Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2016

Significant Accounting Policies [Line Items]

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

Changes in accumulated other comprehensive (loss) earnings, 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 September 30, 2016
Balance at beginning of period	$	(104,114	)	$	(381	)	$	(1,573	)	$	(106,068	)
Other comprehensive earnings (loss) before      reclassifications, net of tax		—			(198	)		—			(198	)
Amounts reclassified from accumulated other      comprehensive earnings, net of tax		1,547			—			208			1,755
Other comprehensive earnings (loss), net of tax		1,547			(198	)		208			1,557
Balance at end of period	$	(102,567	)	$	(579	)	$	(1,365	)	$	(104,511	)
	Three Months Ended September 30, 2015
Balance at beginning of period	$	(111,663	)	$	1,219		$	(2,370	)	$	(112,814	)
Other comprehensive loss before reclassifications,      net of tax		—			(1,757	)		—			(1,757	)
Amounts reclassified from accumulated other      comprehensive earnings, net of tax		1,636			—			193			1,829
Other comprehensive earnings (loss), net of tax		1,636			(1,757	)		193			72
Balance at end of period	$	(110,027	)	$	(538	)	$	(2,177	)	$	(112,742	)

	(Dollars in Thousands)
							Unamortized
							Value of
							Terminated			Accumulated
	Pension and						Forward Starting			Other
	Postretirement			Foreign			Interest Rate			Comprehensive
	Benefit Plans			Currency			Swap			Loss
	Nine Months Ended September 30, 2016
Balance at beginning of period	$	(103,380	)	$	(264	)	$	(1,978	)	$	(105,622	)
Other comprehensive loss before      reclassifications, net of tax		(3,830	)		(315	)		—			(4,145	)
Amounts reclassified from accumulated      other comprehensive earnings, net of tax		4,643			—			613			5,256
Other comprehensive earnings (loss), net of tax		813			(315	)		613			1,111
Balance at end of period	$	(102,567	)	$	(579	)	$	(1,365	)	$	(104,511	)
	Nine Months Ended September 30, 2015
Balance at beginning of period	$	(106,688	)	$	3,278		$	(2,749	)	$	(106,159	)
Other comprehensive loss before      reclassifications, net of tax		(10,845	)		(3,816	)		—			(14,661	)
Amounts reclassified from accumulated      other comprehensive earnings, net of tax		7,506			—			572			8,078
Other comprehensive (loss) earnings, net of tax		(3,339	)		(3,816	)		572			(6,583	)
Balance at end of period	$	(110,027	)	$	(538	)	$	(2,177	)	$	(112,742	)

Noncurrent Deferred Tax Assets Recorded In Accumulated Other Comprehensive Loss

1. Significant Accounting Policies (continued)

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

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 September 30, 2016
Balance at beginning of period	$	66,931		$	1,023		$	67,954
Tax effect of other comprehensive earnings		(986	)		(136	)		(1,122	)
Balance at end of period	$	65,945		$	887		$	66,832
	Three Months Ended September 30, 2015
Balance at beginning of period	$	71,625		$	1,554		$	73,179
Tax effect of other comprehensive earnings		(1,042	)		(125	)		(1,167	)
Balance at end of period	$	70,583		$	1,429		$	72,012
	Nine Months Ended September 30, 2016
Balance at beginning of period	$	66,467		$	1,290		$	67,757
Tax effect of other comprehensive earnings		(522	)		(403	)		(925	)
Balance at end of period	$	65,945		$	887		$	66,832
	Nine Months Ended September 30, 2015
Balance at beginning of period	$	68,568		$	1,799		$	70,367
Tax effect of other comprehensive earnings		2,015			(370	)		1,645
Balance at end of period	$	70,583		$	1,429		$	72,012

Reclassification Out of Accumulated Other Comprehensive Loss

Reclassifications out of accumulated other comprehensive loss are as follows:

	Three Months Ended						Nine Months Ended						Affected line items in the consolidated
	September 30,						September 30,						statements of earnings and
	2016			2015			2016			2015			comprehensive earnings
	(Dollars in Thousands)
Pension and postretirement      benefit plans
Settlement charge	$	—		$	—		$	59		$	—
Amortization of:
Prior service credit		(404	)		(468	)	$	(1,209	)	$	(1,407	)
Actuarial loss		2,893			3,146			8,681			13,691
		2,489			2,678			7,531			12,284		Cost of sales; Selling, general      and administrative expenses
Tax benefit		(942	)		(1,042	)		(2,888	)		(4,778	)	Taxes on income
	$	1,547		$	1,636		$	4,643		$	7,506
Unamortized value of      terminated forward starting      interest rate swap
Additional interest expense	$	344		$	318		$	1,016		$	942		Interest expense
Tax benefit		(136	)		(125	)		(403	)		(370	)	Taxes on income
	$	208		$	193		$	613		$	572

Basic and Diluted Earnings per Common Share

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

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
	(In Thousands)
Net earnings attributable to Martin Marietta Materials, Inc.	$	159,479	$	117,544	$	326,526	$	205,607
Less: Distributed and undistributed earnings attributable to      unvested awards		637		479		1,388		897
Basic and diluted net earnings available to common      shareholders attributable to Martin Marietta Materials, Inc.	$	158,842	$	117,065	$	325,138	$	204,710
Basic weighted-average common shares outstanding		63,452		66,830		63,713		67,203
Effect of dilutive employee and director awards		271		278		254		267
Diluted weighted-average common shares outstanding		63,723		67,108		63,967		67,470

Parent

Significant Accounting Policies [Line Items]

Comprehensive Earnings

Comprehensive earnings attributable to Martin Marietta is as follows:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
	(Dollars in Thousands)
Net earnings attributable to Martin Marietta     Materials, Inc.	$	159,479	$	117,544	$	326,526	$	205,607
Other comprehensive earnings (loss), net of tax		1,557		72		1,111		(6,583	)
Comprehensive earnings attributable to Martin Marietta      Materials, Inc.	$	161,036	$	117,616	$	327,637	$	199,024

Noncontrolling Interests

Significant Accounting Policies [Line Items]

Comprehensive Earnings

1. Significant Accounting Policies (continued)

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

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					Nine Months Ended
	September 30,					September 30,
	2016			2015		2016		2015
	(Dollars in Thousands)
Net (loss) earnings attributable to noncontrolling      interests	$	(1	)	$	34	$	121	$	108
Other comprehensive earnings, net of tax		20			3		52		8
Comprehensive earnings attributable to noncontrolling      interests	$	19		$	37	$	173	$	116