Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

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 March 31, 2018
Balance at beginning of period	$	(128,802	)	$	(22	)	$	(280	)	$	(129,104	)
Other comprehensive loss before    reclassifications, net of tax		—			(587	)		—			(587	)
Amounts reclassified from accumulated    other comprehensive earnings, net of tax		1,996			—			210			2,206
Other comprehensive earnings (loss), net of tax		1,996			(587	)		210			1,619
Balance at end of period	$	(126,806	)	$	(609	)	$	(70	)	$	(127,485	)
	Three-Months Ended March 31, 2017
Balance at beginning of period	$	(128,373	)	$	(1,162	)	$	(1,152	)	$	(130,687	)
Other comprehensive earnings before    reclassifications, net of tax		—			137			—			137
Amounts reclassified from accumulated    other comprehensive earnings, net of tax		1,910			—			215			2,125
Other comprehensive earnings, net of tax		1,910			137			215			2,262
Balance at end of period	$	(126,463	)	$	(1,025	)	$	(937	)	$	(128,425	)

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 March 31, 2018
Balance at beginning of period	$	79,938		$	178		$	80,116
Tax effect of other comprehensive earnings		(658	)		(137	)		(795	)
Balance at end of period	$	79,280		$	41		$	79,321
	Three-Months Ended March 31, 2017
Balance at beginning of period	$	82,044		$	749		$	82,793
Tax effect of other comprehensive earnings		(1,185	)		(141	)		(1,326	)
Balance at end of period	$	80,859		$	608		$	81,467

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						Affected line items in the consolidated
	March 31,						statements of earnings and
	2018			2017			comprehensive earnings
	(Dollars in Thousands)
Pension and postretirement benefit plans
Amortization of:
Prior service credit	$	(585	)	$	(357	)
Actuarial loss		3,239			3,452
		2,654			3,095		Other nonoperating income, net
Tax benefit		(658	)		(1,185	)	Income tax expense
	$	1,996		$	1,910
Unamortized value of terminated    forward starting interest rate swap
Additional interest expense	$	347		$	356		Interest expense
Tax benefit		(137	)		(141	)	Income tax expense
	$	210		$	215

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
	March 31,
	2018		2017
	(In Thousands)
Net earnings attributable to Martin Marietta Materials, Inc.	$	10,023	$	42,334
Less: Distributed and undistributed earnings    attributable to unvested awards		63		153
Basic and diluted net earnings available to common shareholders    attributable to Martin Marietta Materials, Inc.	$	9,960	$	42,181
Basic weighted-average common shares outstanding		62,957		63,024
Effect of dilutive employee and director awards		265		295
Diluted weighted-average common shares outstanding		63,222		63,319

Parent

Significant Accounting Policies [Line Items]

Comprehensive Earnings

Comprehensive earnings attributable to Martin Marietta is as follows:

	Three-Months Ended
	March 31,
	2018		2017
	(Dollars in Thousands)
Net earnings attributable to Martin Marietta Materials, Inc.	$	10,023	$	42,334
Other comprehensive earnings, net of tax		1,619		2,262
Comprehensive earnings attributable to Martin Marietta    Materials, Inc.	$	11,642	$	44,596

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
	March 31,
	2018		2017
	(Dollars in Thousands)
Net earnings (loss) attributable to noncontrolling interests	$	17	$	(27	)
Other comprehensive earnings, net of tax		—		1
Comprehensive earnings (loss) attributable to    noncontrolling interests	$	17	$	(26	)