Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2021

Significant Accounting Policies [Line Items]

Changes in Accumulated Other Comprehensive Loss Net of Tax

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

	(Dollars in Millions)
	Pension and Postretirement Benefit Plans			Foreign Currency			Accumulated Other Comprehensive Loss
	Three Months Ended March 31, 2021
Balance at beginning of period	$	(158.1	)	$	(0.3	)	$	(158.4	)
Other comprehensive earnings before reclassifications,    net of tax		—			0.3			0.3
Amounts reclassified from accumulated other    comprehensive earnings, net of tax		2.5			—			2.5
Other comprehensive earnings, net of tax		2.5			0.3			2.8
Balance at end of period	$	(155.6	)	$	—		$	(155.6	)
	Three Months Ended March 31, 2020
Balance at beginning of period	$	(144.9	)	$	(0.9	)	$	(145.8	)
Other comprehensive loss before reclassifications,    net of tax		—			(2.1	)		(2.1	)
Amounts reclassified from accumulated other    comprehensive loss, net of tax		2.5			—			2.5
Other comprehensive earnings (loss), net of tax		2.5			(2.1	)		0.4
Balance at end of period	$	(142.4	)	$	(3.0	)	$	(145.4	)

Noncurrent Deferred Tax Assets Recorded In Accumulated Other Comprehensive Loss

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

	Pension and Postretirement Benefit Plans
	Three Months Ended
	March 31,
	2021			2020
	(Dollars in Millions)
Balance at beginning of period	$	89.4		$	85.2
Tax effect of other comprehensive earnings		(0.7	)		(0.8	)
Balance at end of period	$	88.7		$	84.4

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
	2021			2020			comprehensive earnings
	(Dollars in Millions)
Pension and postretirement    benefit plans
Amortization of:
Actuarial loss	$	3.2		$	3.3		Other nonoperating (income) and expenses, net
Tax benefit		(0.7	)		(0.8	)	Income tax expense
	$	2.5		$	2.5

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,
	2021		2020
	(In Millions)
Net earnings attributable to Martin Marietta	$	65.3	$	25.9
Less: Distributed and undistributed earnings    attributable to unvested awards		0.1		—
Basic and diluted net earnings available to common    shareholders attributable to Martin Marietta	$	65.2	$	25.9
Basic weighted-average common shares outstanding		62.3		62.3
Effect of dilutive employee and director awards		0.2		0.2
Diluted weighted-average common shares outstanding		62.5		62.5

Reconciliation of Cash, Cash Equivalents and Restricted Cash

The following table reconciles cash, cash equivalents and restricted cash as reported on the consolidated balance sheets to the aggregated amounts presented on the consolidated statements of cash flows:

	March 31,		December 31,
	2021		2020
	(Dollars in Millions)
Cash and cash equivalents	$	313.9	$	207.3
Restricted cash		40.9		97.1
Total cash, cash equivalents and restricted cash presented in    the consolidated statements of cash flows	$	354.8	$	304.4

Parent

Significant Accounting Policies [Line Items]

Comprehensive Earnings

Comprehensive earnings attributable to Martin Marietta is as follows:

	Three Months Ended
	March 31,
	2021		2020
	(Dollars in Millions)
Net earnings attributable to Martin Marietta	$	65.3	$	25.9
Other comprehensive earnings, net of tax		2.8		0.4
Comprehensive earnings attributable to Martin Marietta	$	68.1	$	26.3