Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 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 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	)
	Three Months Ended March 31, 2016
Balance at beginning of period	$	(103,380	)	$	(264	)	$	(1,978	)	$	(105,622	)
Other comprehensive earnings before      reclassifications, net of tax		—			115			—			115
Amounts reclassified from accumulated other      comprehensive earnings, net of tax		1,473			—			201			1,674
Other comprehensive earnings, net of tax		1,473			115			201			1,789
Balance at end of period	$	(101,907	)	$	(149	)	$	(1,777	)	$	(103,833	)

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, 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
	Three Months Ended March 31, 2016
Balance at beginning of period	$	66,467		$	1,290		$	67,757
Tax effect of other comprehensive earnings		(944	)		(131	)		(1,075	)
Balance at end of period	$	65,523		$	1,159		$	66,682

Reclassification Out of Accumulated Other Comprehensive Loss

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
	2017			2016			comprehensive earnings
	(Dollars in Thousands)
Pension and postretirement      benefit plans
Settlement charge	$	—		$	59
Amortization of:
Prior service credit		(357	)		(374	)
Actuarial loss		3,452			2,732
		3,095			2,417		Nonoperating expenses
Tax benefit		(1,185	)		(944	)	Taxes on income
	$	1,910		$	1,473
Unamortized value of terminated      forward starting interest      rate swap
Additional interest expense	$	356		$	332		Interest expense
Tax benefit		(141	)		(131	)	Taxes on income
	$	215		$	201

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
	March 31,
	2017		2016
	(In Thousands)
Net earnings from continuing operations attributable to       Martin Marietta Materials, Inc.	$	42,334	$	44,994
Less: Distributed and undistributed earnings attributable to      unvested awards		153		298
Basic and diluted net earnings available to common      shareholders attributable to Martin Marietta Materials, Inc.	$	42,181	$	44,696
Basic weighted-average common shares outstanding		63,024		64,158
Effect of dilutive employee and director awards		295		192
Diluted weighted-average common shares outstanding		63,319		64,350

Parent

Significant Accounting Policies [Line Items]

Comprehensive Earnings

Comprehensive earnings attributable to Martin Marietta is as follows:

	Three Months Ended
	March 31,
	2017		2016
	(Dollars in Thousands)
Net earnings attributable to Martin Marietta Materials, Inc.	$	42,334	$	44,994
Other comprehensive earnings, net of tax		2,262		1,789
Comprehensive earnings attributable to Martin Marietta Materials, Inc.	$	44,596	$	46,783

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,
	2017			2016
	(Dollars in Thousands)
Net (loss) earnings attributable to noncontrolling interests	$	(27	)	$	61
Other comprehensive earnings, net of tax		1			31
Comprehensive (loss) earnings attributable to noncontrolling interests	$	(26	)	$	92