Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2022

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			Total
	Three Months Ended March 31, 2022
Balance at beginning of period	$	(97.6	)	$	—		$	(97.6	)
Other comprehensive (loss) earnings before reclassifications,    net of tax		(33.3	)		0.4			(32.9	)
Amounts reclassified from accumulated other    comprehensive loss, net of tax		1.3			—			1.3
Other comprehensive (loss) earnings, net of tax		(32.0	)		0.4			(31.6	)
Balance at end of period	$	(129.6	)	$	0.4		$	(129.2	)
	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 loss, 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	)

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,
	2022		2021
	(Dollars in Millions)
Balance at beginning of period	$	69.7	$	89.4
Tax effect of other comprehensive loss (earnings)		10.5		(0.7	)
Balance at end of period	$	80.2	$	88.7

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
	March 31,						consolidated statements of earnings
	2022			2021			and comprehensive earnings
	(Dollars in Millions)
Pension and postretirement    benefit plans
Amortization of:
Prior service credit	$	1.0		$	—
Actuarial loss		0.8			3.2
		1.8			3.2		Other nonoperating income, net
Tax benefit		(0.5	)		(0.7	)	Income tax expense
	$	1.3		$	2.5

Basic and Diluted Earnings from Continuing Operations Per Common Share

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

	Three Months Ended
	March 31,
	2022		2021
	(In Millions)
Net earnings from continuing operations attributable to    Martin Marietta	$	24.5	$	65.3
Less: Distributed and undistributed earnings    attributable to unvested awards		—		0.1
Basic and diluted net earnings from continuing operations available    to common shareholders attributable to Martin Marietta	$	24.5	$	65.2
Basic weighted-average common shares outstanding		62.4		62.3
Effect of dilutive employee and director awards		0.2		0.2
Diluted weighted-average common shares outstanding		62.6		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,
	2022		2021
	(Dollars in Millions)
Cash and cash equivalents	$	189.6	$	258.4
Restricted cash		—		0.5
Total cash, cash equivalents and restricted cash presented in    the consolidated statements of cash flows	$	189.6	$	258.9

Parent

Significant Accounting Policies [Line Items]

Comprehensive (Loss) Earnings

Comprehensive (loss) earnings attributable to Martin Marietta is as follows:

	Three Months Ended
	March 31,
	2022			2021
	(Dollars in Millions)
Net earnings attributable to Martin Marietta	$	21.4		$	65.3
Other comprehensive (loss) earnings, net of tax		(31.6	)		2.8
Comprehensive (loss) earnings attributable to Martin    Marietta	$	(10.2	)	$	68.1