Martin Marietta Materials (MLM) 10-Q 3 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 28, 2014
Document Information	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'MLM	'
Entity Registrant Name	'MARTIN MARIETTA MATERIALS INC	'
Entity Central Index Key	'0000916076	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	67,270,055

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified
Current Assets:	'	'	'
Cash and cash equivalents	$73,597	$42,437	$57,241
Accounts receivable, net	523,928	245,421	331,030
Inventories, net	475,293	347,307	350,438
Current deferred income tax benefits	90,136	74,821	77,005
Other current assets	49,844	45,380	29,955
Total Current Assets	1,212,798	755,366	845,669
Property, plant and equipment	5,624,761	3,976,884	3,942,138
Allowances for depreciation, depletion and amortization	-2,246,810	-2,177,643	-2,159,520
Net property, plant and equipment	3,377,951	1,799,241	1,782,618
Goodwill	2,043,320	616,621	616,634
Operating permits, net	501,734	17,041	17,199
Other intangibles, net	97,488	31,550	31,836
Real estate and other investments	63,766	9,785	10,094
Other noncurrent assets	41,801	30,222	33,055
Total Assets	7,338,858	3,259,826	3,337,105
Current Liabilities:	'	'	'
Bank overdraft	'	2,556	10,437
Accounts payable	230,206	103,600	111,266
Accrued salaries, benefits and payroll taxes	54,062	18,114	20,655
Pension and postretirement benefits	7,351	2,026	1,992
Accrued insurance and other taxes	70,653	29,103	34,444
Current maturities of long-term debt and short-term facilities	14,331	12,403	6,169
Other current liabilities	60,395	42,747	41,469
Total Current Liabilities	436,998	210,549	226,432
Long-term debt	1,603,944	1,018,518	1,107,192
Pension, postretirement and postemployment benefits	144,077	78,489	171,695
Noncurrent deferred income taxes	633,951	279,999	243,858
Other noncurrent liabilities	144,275	97,352	89,045
Total Liabilities	2,963,245	1,684,907	1,838,222
Equity:	'	'	'
Common stock, par value $0.01 per share	671	461	461
Preferred stock, par value $0.01 per share	'	'	'
Additional paid-in capital	3,239,709	432,792	431,122
Accumulated other comprehensive loss	-43,281	-44,114	-102,710
Retained earnings	1,176,121	1,148,738	1,131,276
Total Shareholders' Equity	4,373,220	1,537,877	1,460,149
Noncontrolling interests	2,393	37,042	38,734
Total Equity	4,375,613	1,574,919	1,498,883
Total Liabilities and Equity	$7,338,858	$3,259,826	$3,337,105

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Common stock, par value	$0.01	$0.01	$0.01
Preferred stock, par value	$0.01	$0.01	$0.01

Consolidated_Statements_of_Ear

Consolidated Statements of Earnings and Comprehensive Earnings (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net Sales	$917,942	$600,457	$1,899,557	$1,451,848
Freight and delivery revenues	85,781	64,863	202,021	158,707
Total revenues	1,003,723	665,320	2,101,578	1,610,555
Cost of sales	722,349	457,349	1,542,527	1,188,923
Freight and delivery costs	85,781	64,863	202,021	158,707
Total cost of revenues	808,130	522,212	1,744,548	1,347,630
Gross Profit	195,593	143,108	357,030	262,925
Selling, general & administrative expenses	48,427	37,140	119,239	112,632
Acquisition-related expenses, net	26,118	89	41,178	671
Other operating expenses (income), net	5,092	-2,964	313	-5,535
Earnings from Operations	115,956	108,843	196,300	155,157
Interest expense	19,805	13,518	44,954	40,633
Other nonoperating (income) and expenses, net	-1,841	101	1,330	179
Earnings from continuing operations before taxes on income	97,992	95,224	150,016	114,345
Income tax expense	44,089	22,915	59,571	29,615
Earnings from Continuing Operations	53,903	72,309	90,445	84,730
Loss on discontinued operations, net of related tax benefit of $28, $185, $53 and $250, respectively	-69	-271	-140	-454
Consolidated net earnings	53,834	72,038	90,305	84,276
Less: Net earnings (loss) attributable to noncontrolling interests	91	202	-1,341	-1,028
Net Earnings Attributable to Martin Marietta Materials, Inc.	53,743	71,836	91,646	85,304
Net Earnings Attributable to Martin Marietta Materials, Inc.:	'	'	'	'
Earnings from continuing operations	53,812	72,107	91,786	85,758
Loss from discontinued operations	-69	-271	-140	-454
Net Earnings Attributable to Martin Marietta Materials, Inc.	53,743	71,836	91,646	85,304
Consolidated Comprehensive Earnings: (See Note 1)	'	'	'	'
Comprehensive earnings attributable to Martin Marietta	52,603	75,384	92,479	88,763
Earnings (Loss) attributable to noncontrolling interests	93	205	-1,337	-1,020
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$52,696	$75,589	$91,142	$87,743
Net Earnings (Loss) Attributable to Martin Marietta Materials, Inc. Per Common Share:	'	'	'	'
Basic from continuing operations attributable to common shareholders	$0.80	$1.56	$1.71	$1.85
Discontinued operations attributable to common shareholders	'	($0.01)	'	($0.01)
Earnings Per Share, Basic, Total	$0.80	$1.55	$1.71	$1.84
Diluted from continuing operations attributable to common shareholders	$0.79	$1.55	$1.70	$1.85
Discontinued operations attributable to common shareholders	'	($0.01)	'	($0.01)
Earnings Per Share, Diluted, Total	$0.79	$1.54	$1.70	$1.84
Weighted-Average Common Shares Outstanding:	'	'	'	'
Basic	67,086	46,244	53,342	46,134
Diluted	67,495	46,349	53,559	46,261
Cash Dividends Per Common Share	$0.40	$0.40	$1.20	$1.20

Consolidated_Statements_of_Ear1

Consolidated Statements of Earnings and Comprehensive Earnings (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Loss on discontinued operations, related tax benefit	$28	$185	$53	$250

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash Flows from Operating Activities:	'	'
Consolidated net earnings	$90,305	$84,276
Adjustments to reconcile consolidated net earnings to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	154,079	130,097
Stock-based compensation expense	6,381	5,408
Gains on divestitures and sales of assets	-47,815	-1,003
Deferred income taxes	44,970	19,194
Excess tax benefits from stock-based compensation transactions	-2,354	-1,990
Other items, net	1,766	-739
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:	'	'
Accounts receivable, net	-120,139	-108,134
Inventories, net	1,283	-14,771
Accounts payable	26,515	27,729
Other assets and liabilities, net	46,637	25,578
Net Cash Provided by Operating Activities	201,628	165,645
Cash Flows from Investing Activities:	'	'
Additions to property, plant and equipment	-138,570	-102,342
Acquisitions, net	-174	-64,432
Cash received in acquisition	59,887	'
Proceeds from divestitures and sales of assets	113,158	3,208
Repayments from (Loan to) affiliate	850	-3,402
Payment of railcar construction advances	-14,513	'
Reimbursement of railcar construction advances	14,513	'
Net Cash Provided by (Used for) Investing Activities	35,151	-166,968
Cash Flows from Financing Activities:	'	'
Borrowings of long-term debt	868,762	355,500
Repayments of long-term debt	-1,024,052	-290,192
Payments on capital lease obligations	-2,177	'
Debt issuance costs	-2,402	-510
Change in bank overdraft	-2,556	10,437
Dividends paid	-64,263	-55,626
Purchase of remaining interest in existing subsidiaries	-19,480	'
Issuances of common stock	38,195	11,571
Excess tax benefits from stock-based compensation transactions	2,354	1,990
Net Cash (Used for) Provided by Financing Activities	-205,619	33,170
Net Increase in Cash and Cash Equivalents	31,160	31,847
Cash and Cash Equivalents, beginning of period	42,437	25,394
Cash and Cash Equivalents, end of period	73,597	57,241
Supplemental Disclosures of Cash Flow Information:	'	'
Cash paid for interest	56,162	28,621
Cash paid for income taxes	$6,011	$1,432

Consolidated_Statement_of_Tota

Consolidated Statement of Total Equity (USD $)	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Total Shareholders' Equity	Noncontrolling Interests
In Thousands
Beginning Balance at Dec. 31, 2013	$1,574,919	$461	$432,792	($44,114)	$1,148,738	$1,537,877	$37,042
Beginning Balance (in shares) at Dec. 31, 2013	'	46,261	'	'	'	'	'
Consolidated net earnings	90,305	'	'	'	91,646	91,646	-1,341
Other comprehensive earnings	837	'	'	833	'	833	4
Dividends declared	-64,263	'	'	'	-64,263	-64,263	'
Issuances of common stock, stock options and stock appreciation rights for TXI acquisition (in shares)	'	20,309	'	'	'	'	'
Issuances of common stock, stock options and stock appreciation rights for TXI acquisition	2,751,873	203	2,751,670	'	'	2,751,873	'
Issuances of common stock for stock award plans (in shares)	'	688	'	'	'	'	'
Issuances of common stock for stock award plans	40,474	7	40,467	'	'	40,474	'
Stock-based compensation expense	6,381	'	6,381	'	'	6,381	'
Purchase of remaining interest in existing subsidiaries	-24,913	'	8,399	'	'	8,399	-33,312
Ending Balance at Sep. 30, 2014	$4,375,613	$671	$3,239,709	($43,281)	$1,176,121	$4,373,220	$2,393
Ending Balance (in shares) at Sep. 30, 2014	'	67,258	'	'	'	'	'

Significant_Accounting_Policie

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Significant Accounting Policies	'
	1	Significant Accounting Policies
	Organization
	Martin Marietta (the “Corporation”) is engaged principally in the construction aggregates business. The Corporation’s aggregates product line includes crushed stone, sand and gravel, and is used for construction of highways and other infrastructure projects, and in the nonresidential and residential construction industries. Aggregates products are also used in the railroad, agricultural, utility and environmental industries. These aggregates products, along with the Corporation’s aggregates-related downstream product lines, which include asphalt products, ready mixed concrete and road paving construction services, are sold and shipped from a network of approximately 420 quarries, distribution facilities and plants to customers in 30 states, Canada, the Bahamas and the Caribbean Islands. The aggregates and aggregates-related downstream product lines are reported collectively as the “Aggregates business”.
	Effective January 1, 2014, the Corporation made minor changes to the operations and management reporting structure of its Aggregates business, resulting in an immaterial change to its reportable segments. The Corporation currently conducts the Aggregates business through three reportable segments: the Mid-America Group, the Southeast Group and the West Group.
	AGGREGATES BUSINESS
	Reportable Segments		Mid-America Group		Southeast Group	West Group
	Operating Locations		Indiana, Iowa,		Alabama, Florida,	Arkansas,
			northern Kansas,		Georgia,	Colorado,
			Kentucky,		Mississippi,	southern Kansas,
			Maryland,		Tennessee, Nova	Louisiana,
			Minnesota,		Scotia and the	western Nebraska,
			Missouri,		Bahamas	Nevada,
			eastern Nebraska,			Oklahoma, Texas,
			North Carolina,			Utah and
			Ohio, South Carolina,			Wyoming
			Virginia,
			Washington and
			West Virginia
	The Corporation has a Cement segment, which is comprised of cement operations acquired from Texas Industries, Inc. (“TXI”) with production facilities located in Midlothian, Texas, south of Dallas/Fort Worth; Hunter Texas, south of San Antonio; and Oro Grande, near Los Angeles, California. See Note 2 for additional information on the acquisition. The cement business produces Portland and specialty cements, such as masonry and oil well cements. Similar to the Aggregates business, cement is used in infrastructure projects, nonresidential and residential construction, and the railroad, agricultural, utility and environmental industries. The limestone reserves used as a raw material are located on owned property adjacent to each of the plants. The Corporation also operates cement terminals, a packaging facility at the Crestmore plant near Riverside, California, and its Portland cement grinding facility on an as needed basis.
	The Corporation has a Specialty Products segment with manufacturing facilities in Manistee, Michigan and Woodville, Ohio. The Specialty Products segment produces magnesia-based chemicals products used in industrial, agricultural and environmental applications and dolomitic lime sold primarily to customers in the steel industry.
	Basis of Presentation
	The accompanying unaudited consolidated financial statements of the Corporation have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to the Quarterly Report on Form 10-Q and in Article 10 of Regulation S-X. Other than the adoption of a new accounting standard (see page 9), the Corporation has continued to follow the accounting policies set forth in the audited consolidated financial statements and related notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2013. In the opinion of management, the interim consolidated financial information provided herein reflects all adjustments, consisting of normal recurring accruals, necessary for a fair presentation of the results of operations, financial position and cash flows for the interim periods. The consolidated results of operations for the three and nine months ended September 30, 2014 are not indicative of the results expected for other interim periods or the full year. The consolidated balance sheet at December 31, 2013 has been derived from the audited consolidated financial statements at that date but does not include all of the information and notes required by generally accepted accounting principles for complete financial statements. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2013.
	Early Adoption of New Accounting Standard
	Effective January 1, 2014, the Corporation early adopted the Financial Accounting Standard Board’s (the “FASB”) final guidance on reporting discontinued operations. The guidance is to be applied prospectively and redefines discontinued operations to be either 1) a component of an entity or group of components that has been disposed of or is classified as held for sale that represents a strategic shift that has or will have a major effect on an entity’s operations and financial results or 2) a business that, upon acquisition, meets the criteria to be classified as held for sale. The adoption of the accounting standard did not have any effect on the Corporation’s financial position or results of operations.
	Revenue Recognition Standard
	The FASB issued an accounting standard update that amends the accounting guidance on revenue recognition. The new standard intends to provide a more robust framework for addressing revenue issues, improve comparability of revenue recognition practices and improve disclosure requirements. The new standard is effective for interim and annual reporting periods beginning after December 15, 2016 and can be applied on a full retrospective or modified retrospective approach. The Corporation is currently evaluating the impact of the provisions of the new standard, and at this time does not expect the impact to be material to its results of operations.
	Reclassifications
	Prior-year segment information for the Aggregates business presented in Note 10 has been reclassified to conform to the presentation of the Corporation’s current reportable segments. In addition, certain other reclassifications have been made to prior year amounts to conform to the current year presentation.
	Consolidated Comprehensive Earnings/Loss and Accumulated Other Comprehensive Loss
	Consolidated comprehensive earnings/loss for the Corporation consist of consolidated net earnings or loss; adjustments for the funded status of pension and postretirement benefit plans; foreign currency translation adjustments; and the amortization of the value of terminated forward starting interest rate swap agreements into interest expense, and are presented in the Corporation’s consolidated statements of earnings and comprehensive earnings.
	Comprehensive earnings attributable to Martin Marietta is as follows:
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
			(Dollars in Thousands)
	Net earnings attributable to Martin Marietta		$	53,743		$	71,836		$	91,646		$	85,304
	Other comprehensive (loss) earnings, net of tax			(1,140	)		3,548			833			3,459
	Comprehensive earnings attributable to Martin Marietta		$	52,603		$	75,384		$	92,479		$	88,763
	Comprehensive earnings (loss) attributable to noncontrolling interests, consisting of net earnings or loss 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,
			2014			2013			2014			2013
			(Dollars in Thousands)
	Net earnings (loss) attributable to noncontrolling interests		$	91		$	202		$	(1,341	)	$	(1,028	)
	Other comprehensive earnings, net of tax			2			3			4			8
	Comprehensive earnings (loss) attributable to noncontrolling interests		$	93		$	205		$	(1,337	)	$	(1,020	)
	Accumulated other comprehensive loss consists of unrealized gains and losses related to the funded status of pension and postretirement benefit plans; foreign currency translation; and the unamortized value of terminated forward starting interest rate swap agreements, and is presented on the Corporation’s consolidated balance sheets. Changes in accumulated other comprehensive loss, net of tax, are as follows:
			(Dollars in Thousands)
			Pension and			Foreign			Unamortized			Accumulated
			Postretirement			Currency			Value of			Other
			Benefit Plans						Terminated			Comprehensive
									Forward			Loss
									Starting
									Interest Rate
									Swap
			Three Months Ended September 30, 2014
	Balance at beginning of period		$	(44,685	)	$	5,658		$	(3,114	)	$	(42,141	)
	Other comprehensive loss before reclassifications, net of tax			—			(1,466	)		—			(1,466	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax			146			—			180			326
	Other comprehensive earnings (loss), net of tax			146			(1,466	)		180			(1,140	)
	Balance at end of period		$	(44,539	)	$	4,192		$	(2,934	)	$	(43,281	)
			Three Months Ended September 30, 2013
	Balance at beginning of period		$	(106,603	)	$	4,153		$	(3,808	)	$	(106,258	)
Other comprehensive earnings before reclassifications, net of tax			—			993			—			993
Amounts reclassified from accumulated other comprehensive loss, net of tax			2,387			—			168			2,555
Other comprehensive earnings, net of tax			2,387			993			168			3,548
Balance at end of period		$	(104,216	)	$	5,146		$	(3,640	)	$	(102,710	)
		(Dollars in Thousands)
		Pension and			Foreign			Unamortized			Accumulated
		Postretirement			Currency			Value of			Other
		Benefit Plans						Terminated			Comprehensive
								Forward			Loss
								Starting
								Interest Rate
								Swap
		Nine Months Ended September 30, 2014
Balance at beginning of period		$	(44,549	)	$	3,902		$	(3,467	)	$	(44,114	)
Other comprehensive (loss ) earnings before reclassifications, net of tax			(431	)		290			—			(141	)
Amounts reclassified from accumulated other comprehensive loss, net of tax			441			—			533			974
Other comprehensive earnings, net of tax			10			290			533			833
Balance at end of period		$	(44,539	)	$	4,192		$	(2,934	)	$	(43,281	)
		Nine Months Ended September 30, 2013
Balance at beginning of period		$	(108,189	)	$	6,157		$	(4,137	)	$	(106,169	)
Other comprehensive loss before reclassifications, net of tax			(2,312	)		(1,011	)		—			(3,323	)
Amounts reclassified from accumulated other comprehensive loss, net of tax			6,285			—			497			6,782
Other comprehensive earnings (loss), net of tax			3,973			(1,011	)		497			3,459
Balance at end of period		$	(104,216	)	$	5,146		$	(3,640	)	$	(102,710	)
The other comprehensive loss before reclassifications for pension and postretirement benefit plans is net of tax of $280,000 and $1,514,000 for the nine months ended September 30, 2014 and 2013, respectively.
Changes in net noncurrent deferred tax assets recorded in accumulated other comprehensive loss are as follows:
		(Dollars in Thousands)
		Pension and			Unamortized Value			Net Noncurrent
		Postretirement			of Terminated			Deferred Tax
		Benefit Plans			Forward Starting			Assets
					Interest Rate Swap
		Three Months Ended September 30, 2014
Balance at beginning of period		$	29,287		$	2,039		$	31,326
Tax effect of other comprehensive earnings			(96	)		(120	)		(216	)
Balance at end of period		$	29,191		$	1,919		$	31,110
		Three Months Ended September 30, 2013
Balance at beginning of period		$	69,842		$	2,492		$	72,334
Tax effect of other comprehensive earnings			(1,566	)		(111	)		(1,677	)
Balance at end of period		$	68,276		$	2,381		$	70,657
		Nine Months Ended September 30, 2014
Balance at beginning of period		$	29,198		$	2,269		$	31,467
Tax effect of other comprehensive earnings			(7	)		(350	)		(357	)
Balance at end of period		$	29,191		$	1,919		$	31,110
		Nine Months Ended September 30, 2013
Balance at beginning of period		$	70,881		$	2,707		$	73,588
Tax effect of other comprehensive earnings			(2,605	)		(326	)		(2,931	)
Balance at end of period		$	68,276		$	2,381		$	70,657
Reclassifications out of accumulated other comprehensive loss are as follows:
		Three Months Ended						Nine Months Ended						Affected line items in
		September 30,						September 30,
		2014			2013			2014			2013			the consolidated
														financial statements
		(Dollars in Thousands)
Pension and postretirement benefit plans
Settlement expense		$	—		$	729		$	—		$	729
Amortization of:
Prior service credit			(703	)		(702	)		(2,107	)		(2,104	)
Actuarial loss			945			3,926			2,835			11,779
			242			3,953			728			10,404		Cost of sales;
														Selling, general & administrative expenses
Tax effect			(96	)		(1,566	)		(287	)		(4,119	)	Deferred income taxes
		$	146		$	2,387		$	441		$	6,285
Unamortized value of terminated forward starting interest rate swap
Additional interest expense		$	300		$	279		$	883		$	823		Interest expense
Tax effect			(120	)		(111	)		(350	)		(326	)	Deferred income taxes
		$	180		$	168		$	533		$	497
Earnings per Common Share
The numerator for basic and diluted earnings per common share is net earnings/loss attributable to Martin Marietta reduced by dividends and undistributed earnings attributable to the Corporation’s unvested restricted stock awards and incentive stock awards. If there is a net loss, no amount of the undistributed loss is attributed to unvested participating securities. The denominator for basic earnings per common share is the weighted-average number of common shares outstanding during the period. Diluted earnings per common share are computed assuming that the weighted-average number of common shares is increased by the conversion, using the treasury stock method, of awards to be issued to employees and nonemployee members of the Corporation’s Board of Directors under certain stock-based compensation arrangements if the conversion is dilutive. For the three and nine months ended September 30, 2014 and 2013, the diluted per-share computations reflect a change in the number of common shares outstanding to include the number of additional shares that would have been outstanding if the potentially dilutive common shares had been issued.
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,
		2014			2013			2014			2013
		(Dollars in Thousands)
Net earnings from continuing operations attributable to Martin Marietta		$	53,812		$	72,107		$	91,786		$	85,758
Less: Distributed and undistributed earnings attributable to unvested awards			213			265			372			374
Basic and diluted net earnings available to common shareholders from continuing operations attributable to Martin Marietta			53,599			71,842			91,414			85,384
Basic and diluted net loss available to common shareholders from discontinued operations			(69	)		(271	)		(140	)		(454	)
Basic and diluted net earnings available to common shareholders attributable to Martin Marietta		$	53,530		$	71,571		$	91,274		$	84,930
Basic weighted-average common shares outstanding			67,086			46,244			53,342			46,134
Effect of dilutive employee and director awards			409			105			217			127
Diluted weighted-average common shares outstanding			67,495			46,349			53,559			46,261

Business_Combinations_and_Dive

Business Combinations and Divestitures	9 Months Ended
	Sep. 30, 2014
Business Combinations and Divestitures	'
	2	Business Combinations and Divestitures
	TXI Business Combination
	On July 1, 2014, pursuant to the merger agreement (the “Merger Agreement”) dated as of January 27, 2014 by and among the Corporation, Project Holdings, Inc., a wholly-owned subsidiary of the Corporation (“Merger Sub”), and TXI, Merger Sub merged with and into TXI, with TXI surviving as a wholly-owned subsidiary of the Corporation (the “Merger”). As a result of the Merger, each outstanding share of TXI common stock (other than shares owned by TXI, the Corporation or Merger Sub, which were cancelled) was converted into 0.70 shares of the Corporation’s common stock, with cash paid in lieu of fractional shares. The Corporation issued 20,309,000 shares of its common stock to former TXI stockholders in connection with the Merger. Based on the Corporation’s closing stock price on July 1, 2014 of $132.00, the aggregate value of the Corporation’s common stock delivered to former TXI stockholders was $2,680,788,000. Additionally, the fair value of outstanding TXI stock options and stock appreciation rights that were converted into Martin Marietta stock awards at the acquisition date of $71,085,000 and shares withheld for income tax obligations were components of the total consideration, which was $2,756,934,000.
	TXI was the largest producer of cement in Texas and a major cement producer in California. TXI was also a major supplier of construction aggregate, ready mixed concrete and concrete products. The combination expands the Corporation’s geographic footprint and positions the Corporation to benefit from the strength of the combined aggregates platform.
	The Corporation has determined preliminary fair values of the assets acquired and liabilities assumed. Although initial accounting for the business combination has been recorded, these amounts are subject to change based on the final valuation report and additional reviews performed, such as asset verification. Specific accounts subject to ongoing purchase accounting adjustments include but are not limited to inventory; property, plant and equipment; other assets; goodwill; accounts payable and accrued expenses and deferred taxes. Therefore, the measurement period remains open as of September 30, 2014. The following is a summary of the estimated fair values of the assets acquired and the liabilities assumed (dollars in thousands).
	Assets:
	Cash and cash equivalents		$	59,887
	Receivables			161,437
	Inventory			132,972
	Other current assets			56,246
	Property, plant and equipment			1,608,305
	Real estate and other investments			59,584
	Intangible assets, other than goodwill			559,327
	Other noncurrent assets			5,367
	Goodwill			1,457,043
	Total assets			4,100,168
	Liabilities:
	Accounts payable and accrued expenses			259,723
	Notes and contracts payable and capital leases			745,217
	Deferred income tax liabilities			338,294
	Total liabilities			1,343,234
	Total consideration		$	2,756,934
	Real estate and other investments include property held for resale and a noncontrolling interest in a joint venture.
	Goodwill represents the excess purchase price over the fair values of assets acquired and liabilities assumed. The goodwill was generated by the synergies the transaction provides, including overhead savings, purchasing leverage generated by a larger company, benefits of the existing long-haul transportation system, and cost savings achieved through increased vertical integration of the business. None of the goodwill generated by the transaction will be deductible for income tax purposes.
	Total revenues and earnings from operations included in the consolidated earnings statements attributable to TXI operations as of September 30, 2014 are $287,587,000 and $18,755,000, respectively.
	Business development and acquisition integration expenses related to the TXI acquisition were $73,968,000 and $88,959,000 for the three and nine months ended September 30, 2014, respectively.
	Unaudited Pro Forma Financial Information
	The unaudited pro forma financial information in the table below summarizes the combined results of operations for the Corporation and TXI as though the companies were combined as of January 1, 2013. Transactions between Martin Marietta and TXI during the periods presented in the pro forma financial statements have been eliminated as if Martin Marietta and TXI were consolidated affiliates during the periods. Financial information for periods prior to the July 1, 2014 acquisition date included in the pro forma earnings does not reflect any cost savings or associated costs to achieve such savings from operating efficiencies, synergies, debt refinancing, utilization of TXI net operating loss carryforwards or other restructuring that result from the combination. The pro forma financial information for the nine months ended September 30, 2014 reflects the elimination of business development and acquisition integration expenses and the gain on the required divestiture of assets.
	The unaudited pro forma financial information for the nine months ended September 30, 2014 includes TXI’s historical operating results for the six months ended May 31, 2014 (due to a difference in TXI’s historical reporting periods) and the results of operations for the TXI locations from July 1, 2014, the acquisition date, to September 30, 2014. The unaudited pro forma financial information for the three and nine months ended September 30, 2013 includes the historical results of TXI for the three and nine months ended August 31, 2013 (due to a difference in TXI’s historical reporting periods).
	The pro forma financial statements do not purport to project the future financial position or operating results of the combined company. The pro forma financial information as presented below is for informational purposes only and is not indicative of the results of operations that would have been achieved if the acquisitions had taken place at the beginning of fiscal year 2013.
			Three Months Ended		Nine Months Ended
			September 30,		September 30,
			2013		2014		2013
			(Dollars in Thousands)
	Net sales		$	802,575	$	2,309,104	$	1,962,216
	Earnings from continuing operations attributable to controlling interest		$	67,930	$	106,928	$	83,661
	Divestiture of Assets
	In accordance with an agreement between the Corporation and the U.S. Department of Justice (“DOJ”) as part of its review of the business combination with TXI, the Corporation agreed to divest a Corporate owned aggregates quarry in Oklahoma and two Corporate owned rail yards in Texas. On August 15, 2014, the Corporation divested of the properties in exchange for cash and real property and recognized a pretax gain of $47,904,000, which is included in acquisition-related expenses, net, in the consolidated statements of earnings and comprehensive earnings.
	Purchase of Remaining Interest in Existing Subsidiaries
	During 2014, the Corporation acquired the remaining interest in two joint ventures in separate transactions. Net cash paid for both transactions was $19,480,000.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets	'
	3	Goodwill and Intangible Assets
	The following table shows the changes in goodwill by reportable segment and in total:
			Mid-America		Southeast			West			Cement		Total
			Group		Group			Group
	(Dollars in Thousands)		Nine Months Ended September 30, 2014
	Balance at January 1, 2014		$	263,967	$	50,346		$	302,308		$	—	$	616,621
	Organizational changes			18,150					(18,150	)				—
	Acquisitions			—		—			614,224			842,819		1,457,043
	Amounts allocated to divestitures			—		—			(30,344	)		—		(30,344	)
	Balance at September 30, 2014		$	282,117	$	50,346		$	868,038		$	842,819	$	2,043,320
			Year Ended December 31, 2013
	Balance at January 1, 2013		$	263,868	$	50,001		$	302,335		$	—	$	616,204
	Acquisitions			99		345						—		444
	Adjustments to purchase price allocations			—		—			(27	)		—		(27	)
	Balance at December 31, 2013		$	263,967	$	50,346		$	302,308		$	—	$	616,621
	Intangible assets subject to amortization consist of the following:
			Gross		Accumulated			Net
			Amount		Amortization			Balance
	(Dollars in Thousands)		September 30, 2014
	Noncompetition agreements		$	6,274	$	(5,874	)	$	400
	Customer relationships			36,610		(6,824	)		29,786
	Operating permits			498,685		(3,551	)		495,134
	Use rights and other			15,386		(6,669	)		8,717
	Trade name			12,800		(572	)		12,228
	Total		$	569,755	$	(23,490	)	$	546,265
			31-Dec-13
	Noncompetition agreements		$	6,274	$	(5,583	)	$	691
	Customer relationships			20,660		(6,160	)		14,500
	Operating permits			6,800		(1,394	)		5,406
	Use rights and other			10,115		(6,156	)		3,959
	Total		$	43,849	$	(19,293	)	$	24,556
	Intangible assets deemed to have an indefinite life and not being amortized consist of the following:
			Aggregates		Cement			Specialty			Total
			Business					Products
	(Dollars in Thousands)		September 30, 2014
	Operating permits		$	6,600	$	—		$	—		$	6,600
	Use rights			9,385		20,027			—			29,412
	Trade name			80		14,300			2,565			16,945
	Total		$	16,065	$	34,327		$	2,565		$	52,957
			31-Dec-13
	Operating permits		$	11,635	$	—		$	—		$	11,635
	Use rights			9,835		—			—			9,835
	Trade name			—		—			2,565			2,565
	Total		$	21,470	$	—		$	2,565		$	24,035
	The Corporation acquired $559,327,000 of intangibles from the TXI acquisition, which consists of the following:
	(Dollars in Thousands)		Amount		Weighted-average
					amortization period
	Subject to amortization:
	Customer relationships		$	20,150	12.0 years
	Operating permits			487,150	87.3 years
	Use rights and other			4,820	8.2 years
	Trade name			12,800	6.0 years
			$	524,920	81.7 years
	Not subject to amortization:
	Use rights		$	20,027	N/A
	Trade name			14,380
				34,407
	Total		$	559,327
	Use rights include, but are not limited to, water rights, subleases and proprietary information.
	Total amortization expense for intangible assets for the nine months ended September 30, 2014 and 2013 was $5,516,000 and $2,692,000, respectively.
	The estimated amortization expense for intangible assets for the three months ending December 31, 2014 and for each of the next five years and thereafter is as follows:
	(Dollars in Thousands)
	Remainder of 2014		$	3,773
2015			14,453
2016			14,149
2017			14,009
2018			13,118
2019			12,192
Thereafter			474,571
Total		$	546,265

Inventories_Net

Inventories, Net	9 Months Ended
	Sep. 30, 2014
Inventories, Net	'
	4	Inventories, Net
			September 30,			December 31,			September 30,
			2014			2013			2013
			(Dollars in Thousands)
	Finished products		$	397,684		$	368,334		$	366,558
	Products in process and raw materials			58,678			16,077			19,924
	Supplies and expendable parts			127,319			61,922			61,441
				583,681			446,333			447,923
	Less: Allowances			(108,388	)		(99,026	)		(97,485	)
	Total		$	475,293		$	347,307		$	350,438

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2014
Long-Term Debt	'
	5	Long-Term Debt
			September 30,			December 31,			September 30,
			2014			2013			2013
			(Dollars in Thousands)
	6.6% Senior Notes, due 2018		$	299,063		$	298,893		$	298,837
	7% Debentures, due 2025			124,493			124,471			124,464
	6.25% Senior Notes, due 2037			228,175			228,148			228,139
	4.25% Senior Notes, due 2024			395,211			—			—
	Floating Rate Notes, due 2017, interest rate of 1.34% at September 30, 2014			298,760			—			—
	Term Loan Facility, due 2018, interest rate of 1.65% at September 30, 2014; 1.67% at December 31, 2013; and 2.20% at September 30, 2013			239,304			248,441			240,000
	Revolving Facility, interest rate of 1.89% at September 30, 2013			—			—			70,000
	Trade Receivable Facility, interest rate of 0.76% at September 30, 2014; 0.77% at December 31, 2013; and 0.79% at September 30, 2013			30,000			130,000			150,000
	Other notes			3,269			968			1,921
	Total debt			1,618,275			1,030,921			1,113,361
	Less: Current maturities			(14,331	)		(12,403	)		(6,169	)
	Long-term debt		$	1,603,944		$	1,018,518		$	1,107,192
	On June 23, 2014, the Corporation priced its offering of $300,000,000 aggregate principal amount of its Floating Rate Senior Notes due 2017 (the “Floating Rate Notes”) and $400,000,000 of its 4.25% Senior Notes due 2024 (the “4.25% Senior Notes” and together with the Floating Rate Notes, the “Notes”). The bond transaction closed and settlement occurred on July 2, 2014. In connection with the issuance of the Notes, the Corporation entered into an indenture, dated as of July 2, 2014, between the Corporation and Regions Bank, as trustee, and a Registration Rights Agreement, dated as of July 2, 2014, with respect to the Notes, among the Corporation, Deutsche Bank Securities Inc. and J.P. Morgan Securities LLC, as representatives of the several initial purchasers named in Schedule I to the purchase agreement entered into on June 23, 2014 with respect to the Notes. The Floating Rate Notes bear interest at a rate equal to the three-month LIBOR plus 1.10% and may not be redeemed prior to maturity. The 4.25% Senior Notes may be redeemed in whole or in part prior to their maturity at a make-whole redemption price.
	On July 1, 2014, the Corporation, through a wholly-owned special purpose subsidiary, amended its trade receivable securitization facility (the “Trade Receivable Facility”) to increase the borrowing capacity from $150,000,000 to $250,000,000. On September 30, 2014, the Corporation extended the maturity of its Trade Receivable Facility to September 30, 2016. The Trade Receivable Facility, with Regions Bank and PNC Bank, National Association and certain other lenders that may become a party to the facility from time to time, is backed by eligible trade receivables, as defined, of $482,371,000, $234,101,000 and $314,998,000 at September 30, 2014, December 31, 2013 and September 30, 2013, respectively. These receivables are originated by the Corporation and then sold to the wholly-owned special purpose subsidiary by the Corporation. The Corporation continues to be responsible for the servicing and administration of the receivables purchased by the wholly-owned special purpose subsidiary. The Trade Receivable Facility contains a cross-default provision to the Corporation’s other debt agreements.
	The Corporation’s Credit Agreement, which provides a $250,000,000 senior unsecured term loan (the “Term Loan Facility”) and a $350,000,000 five-year senior unsecured revolving facility (the “Revolving Facility”), requires the Corporation’s ratio of consolidated debt to consolidated earnings before interest, taxes, depreciation, depletion and amortization (EBITDA), as defined, for the trailing twelve months (the “Ratio”) to not exceed 3.50x as of the end of any fiscal quarter, provided that the Corporation may exclude from the Ratio debt incurred in connection with certain acquisitions for a period of 180 days so long as the Corporation, as a consequence of such specified acquisition, does not have its rating on long-term unsecured debt fall below BBB by Standard & Poor’s or Baa2 by Moody’s and the Ratio calculated without such exclusion does not exceed 3.75x. Additionally, if no amounts are outstanding under both the Revolving Facility and the Trade Receivable Facility, consolidated debt, including debt for which the Corporation is a co-borrower, may be reduced by the Corporation’s unrestricted cash and cash equivalents in excess of $50,000,000, such reduction not to exceed $200,000,000, for purposes of the covenant calculation.
	Effective June 23, 2014, the Corporation amended the Credit Agreement to ensure the impact of the business combination with TXI does not impair liquidity available under the Term Loan Facility and the Revolving Facility. The amendment adjusts consolidated EBITDA to add back fees, costs or expenses relating to the TXI business combination incurred on or prior to the closing of the combination not to exceed $95,000,000; any integration or similar costs or expenses related to the TXI business combination incurred in any period prior to the second anniversary of the closing of the TXI business combination not to exceed $70,000,000; and any make-whole fees incurred in connection with the redemption of TXI’s 9.25% senior notes due 2020. The amendment also temporarily increases the maximum Ratio to 3.75x at September 30, 2014. The Corporation was in compliance with this Ratio at September 30, 2014. The Ratio returns to the pre-amendment maximum of 3.50x for the December 31, 2014 calculation date.
	Available borrowings under the Revolving Facility are reduced by any outstanding letters of credit issued by the Corporation under the Revolving Facility. At September 30, 2014, the Corporation had $2,507,000 of outstanding letters of credit issued under the Revolving Facility.
	Accumulated other comprehensive loss includes the unamortized value of terminated forward starting interest rate swap agreements. For the three and nine months ended September 30, 2014, the Corporation recognized $300,000 and $883,000, respectively, as additional interest expense. For the three and nine months ended September 30, 2013, the Corporation recognized $279,000 and $823,000, respectively, as additional interest expense. The ongoing amortization of the terminated value of the forward starting interest rate swap agreements will increase annual interest expense by approximately $1,200,000 until the maturity of the 6.6% Senior Notes in 2018.

Financial_Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2014
Financial Instruments	'
	6	Financial Instruments
	The Corporation’s financial instruments include cash equivalents, accounts receivable, notes receivable, bank overdraft, accounts payable, publicly-registered long-term notes, debentures and other long-term debt.
	Cash equivalents are placed primarily in money market funds, money market demand deposit accounts and Eurodollar time deposits. The Corporation’s cash equivalents have maturities of less than three months. Due to the short maturity of these investments, they are carried on the consolidated balance sheets at cost, which approximates fair value.
	Accounts receivables are due from a large number of customers, primarily in the construction industry, and are dispersed across wide geographic and economic regions. However, accounts receivables are more heavily concentrated in certain states (namely, Texas, North Carolina, Colorado, Iowa and Georgia). The estimated fair values of customer receivables approximate their carrying amounts due to the short-term nature of the receivables.
	Notes receivable are primarily promissory notes with customers and are not publicly traded. Management estimates that the fair value of notes receivable approximates the carrying amount.
	The bank overdraft represents amounts to be funded to financial institutions for checks that have cleared the bank. The estimated fair value of the bank overdraft approximates its carrying value.
	Accounts payable represent amounts owed to suppliers and vendors. The estimated fair value of accounts payable approximates its carrying amounts due to the short-term nature of the payables.
	The carrying values and fair values of the Corporation’s long-term debt were $1,618,275,000 and $1,707,920,000, respectively, at September 30, 2014; $1,030,921,000 and $1,068,324,000, respectively, at December 31, 2013; and $1,113,361,000 and $1,152,906,000, respectively, at September 30, 2013. The estimated fair value of the publicly-registered long-term notes was estimated based on Level 1 of the fair value hierarchy using quoted market prices. The fair value of the Notes was based on Level 2 of the fair value hierarchy using quoted market prices for similar debt instruments. The estimated fair value of other borrowings, which primarily represents variable-rate debt, approximates its carrying amount as the interest rates reset periodically.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Taxes	'
	7	Income Taxes
			Nine Months Ended September 30,
			2014			2013
	Estimated effective income tax rate:
	Continuing operations			39.7	%		25.9	%
	Discontinued operations			27.6	%		35.6	%
	Consolidated overall			39.7	%		25.8	%
	The Corporation’s effective income tax rate reflects the effect of federal and state income taxes and the impact of differences in book and tax accounting arising from the net permanent benefits associated with the statutory depletion deduction for mineral reserves, the impact of foreign losses for which no tax benefit was realized and the domestic production deduction. The effective income tax rates for discontinued operations reflect the tax effects of individual operations’ transactions and are not indicative of the Corporation’s overall effective income tax rate.
	The increase in the effective income tax rate in 2014 reflects the impact of goodwill written off as part of a divestiture that is not deductible for income tax purposes. Additionally, certain business development and acquisition integration expenses are only partially deductible for income tax purposes.
	On September 13, 2013, the U.S. Treasury Department and Internal Revenue Service issued final regulations addressing costs incurred in acquiring, producing or improving tangible property (the “tangible property regulations”). The tangible property regulations required the Corporation to make additional tax accounting method changes as of January 1, 2014. As of December 31, 2013, the Corporation estimated the tax impact of the regulatory change and recorded an increase in noncurrent deferred tax liabilities in the amount of $1,334,000, with a corresponding reduction in current taxes payable.
	The Corporation’s unrecognized tax benefits, excluding interest, correlative effects and indirect benefits, are as follows:
			Nine Months Ended
			September 30, 2014
			(Dollars in Thousands)
	Unrecognized tax benefits at beginning of period		$	11,826
	Gross increases – tax positions in prior years			1,898
	Gross decreases – tax positions in prior years			(204	)
	Gross increases – tax positions in current year			1,418
	Gross increases as a result of lapse of statute of limitations			4,442
	Gross decreases as a result of lapse of statute of limitations			(6,314	)
	Increases – uncertain tax positions assumed in connection with an acquisition			5,963
	Unrecognized tax benefits at end of period		$	19,029
	In accordance with Accounting Standard Codification 740, Income Taxes, $5,300,000 of the $5,963,000 of uncertain tax positions assumed in connection with an acquisition is recorded as a reduction of the deferred tax asset for net operating losses.
	The Corporation records interest accrued in relation to unrecognized tax benefits as income tax expense. Penalties, if incurred, are recorded as operating expenses in the consolidated statements of earnings and comprehensive earnings.
	The Corporation anticipates that it is reasonably possible that unrecognized tax benefits may decrease up to $8,530,000, excluding indirect benefits, during the twelve months ending September 30, 2015 as a result of expected settlements with taxing authorities and the expiration of the foreign and domestic statute of limitations for the 2010 and 2011 tax years.
	At September 30, 2014, unrecognized tax benefits of $9,083,000 related to interest accruals and permanent income tax differences, net of federal tax benefits, would have favorably affected the Corporation’s effective income tax rate if recognized.
	The Corporation’s open tax years subject to federal, foreign or state examinations are 2009 through 2013.

Pension_and_Postretirement_Ben

Pension and Postretirement Benefits	9 Months Ended
	Sep. 30, 2014
Pension and Postretirement Benefits	'
	8	Pension and Postretirement Benefits
	As part of the TXI acquisition, the Corporation assumed three defined benefit plans, including two pension plans and one postretirement plan. Inclusive of the TXI plans, the Corporation estimates that calendar-year 2014 contributions to the pension plans will be approximately $25,500,000, of which $1,380,000 will be contributed in the quarter ending December 31, 2014. The expense for the three and nine months ended September 30, 2014 includes the cost for TXI employees from the acquisition date, July 1, 2014, to September 30, 2014. The termination benefit cost represents certain change-in-control provisions that provide enhanced benefits related to former TXI executives. The estimated components of the recorded net periodic benefit cost (credit) for pension and postretirement benefits are as follows:
			Three Months Ended September 30,
			Pension						Postretirement Benefits
			2014			2013			2014			2013
			(Dollars in Thousands)
	Service cost		$	4,996		$	4,030		$	57		$	57
	Interest cost			7,979			5,756			302			253
	Expected return on assets			(8,627	)		(6,668	)		—			—
	Amortization of:
	Prior service cost (credit)			111			112			(814	)		(814	)
	Actuarial loss (gain)			1,011			3,920			(66	)		6
	Settlement charge			—			729			—			—
	Termination benefit cost			13,680			—			—			—
	Net periodic benefit cost (credit)		$	19,150		$	7,879		$	(521	)	$	(498	)
			Nine Months Ended September 30,
			Pension						Postretirement Benefits
			2014			2013			2014			2013
			(Dollars in Thousands)
	Service cost		$	12,129		$	12,091		$	150		$	170
	Interest cost			20,952			17,268			861			760
	Expected return on assets			(24,030	)		(20,003	)		—			—
	Amortization of:
	Prior service cost (credit)			334			337			(2,441	)		(2,441	)
	Actuarial loss (gain)			3,034			11,760			(199	)		19
	Settlement charge			—			729			—			—
	Termination benefit cost			13,680			—			—			—
	Net periodic benefit cost (credit)		$	26,099		$	22,182		$	(1,629	)	$	(1,492	)

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies	'
	9	Commitments and Contingencies
	Legal and Administrative Proceedings
	The Corporation is engaged in certain legal and administrative proceedings incidental to its normal business activities. In the opinion of management and counsel, based upon currently-available facts, it is remote that the ultimate outcome of any litigation and other proceedings, including those pertaining to environmental matters, relating to the Corporation and its subsidiaries, will have a material adverse effect on the overall results of the Corporation’s operations, its cash flows or its financial position.
	Environmental and Governmental Regulations
	The United States Environmental Protection Agency (“EPA”) includes the lime industry as a national enforcement priority under the federal Clean Air Act (“CAA”). As part of the industry wide effort, the EPA issued Notices of Violation/Findings of Violation (“NOVs”) to the Corporation in 2010 and 2011 regarding the Corporation’s compliance with the CAA New Source Review (“NSR”) program at its Specialty Products dolomitic lime manufacturing plant in Woodville, Ohio. The Corporation has been providing information to the EPA in response to these NOVs and has had several meetings with the EPA. The Corporation believes it is in substantial compliance with the NSR program. At this time, the Corporation cannot reasonably estimate what likely penalties or upgrades to equipment might ultimately be required. The Corporation believes that any costs related to any upgrades to capital equipment will be spread over time and will not have a material adverse effect on the Corporation’s results of operations or its financial condition, but can give no assurance that the ultimate resolution of this matter will not have a material adverse effect on the financial condition or results of operations of the Specialty Products segment of the business.
	Borrowing Arrangements with Affiliate
	The Corporation is a co-borrower with an unconsolidated affiliate for a $24,000,000 revolving line of credit agreement with Fifth Third Bank. The affiliate has agreed to reimburse and indemnify the Corporation for any payments and expenses the Corporation may incur from this agreement. The Corporation holds a lien on the affiliate’s membership interest in a joint venture as collateral for payment under the revolving line of credit.
	In September 2013, the Corporation loaned $3,402,000 to this unconsolidated affiliate to repay in full the outstanding balance of the affiliate’s loan with Bank of America, N.A. and entered into a loan agreement with the affiliate for monthly repayment of principal and interest of that loan amount through May 2016. The Corporation holds a lien on the affiliate’s property as collateral for payment under the loan and security agreement. As of September 30, 2014 and December 31, 2013, the amount due from the affiliate related to this loan was $1,605,000 and $2,984,000, respectively.
	In addition, the Corporation has a $6,000,000 outstanding loan due from this unconsolidated affiliate as of September 30, 2014 and December 31, 2013.

Business_Segments

Business Segments	9 Months Ended
	Sep. 30, 2014
Business Segments	'
	10	Business Segments
	The Aggregates business contains three reportable business segments: Mid-America Group, Southeast Group and West Group. The Corporation also has Cement and Specialty Products segments.
	The following tables display selected financial data for continuing operations for the Corporation’s reportable business segments. Corporate loss from operations primarily includes depreciation on capitalized interest, expenses for corporate administrative functions, business development and integration expenses, unallocated corporate expenses and other nonrecurring and/or non-operational adjustments. Intersegment sales represent net sales from one segment to another segment. Total revenues and net sales in the table below, as well as the consolidated statements of earnings and comprehensive earnings, do not include intersegment sales as these sales are eliminated.
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
			(Dollars in Thousands)
	Total revenues:
	Mid-America Group		$	271,096		$	255,737		$	627,331		$	592,794
	Southeast Group			73,217			69,490			208,205			185,676
	West Group			479,323			279,477			956,921			649,896
	Total Aggregates Business			823,636			604,704			1,792,457			1,428,366
	Cement			115,743			—			115,743			—
	Specialty Products			64,344			60,616			193,378			182,189
	Total		$	1,003,723		$	665,320		$	2,101,578		$	1,610,555
	Net sales:
	Mid-America Group		$	244,309		$	231,807		$	569,545		$	540,209
	Southeast Group			68,042			64,871			194,148			171,456
	West Group			437,398			247,985			848,402			572,588
	Total Aggregates Business			749,749			544,663			1,612,095			1,284,253
	Cement			109,521			—			109,521			—
	Specialty Products			58,672			55,794			177,941			167,595
	Total		$	917,942		$	600,457		$	1,899,557		$	1,451,848
	Earnings (Loss) from operations:
	Mid-America Group		$	71,185		$	67,162		$	116,703		$	100,915
	Southeast Group			329			(1,386	)		(7,084	)		(14,949	)
	West Group			92,115			31,559			125,069			39,829
	Total Aggregates Business			163,629			97,335			234,688			125,795
	Cement			18,278			—			18,278			—
	Specialty Products			17,697			17,267			54,976			53,071
	Corporate			(83,648	)		(5,759	)		(111,642	)		(23,709	)
	Total		$	115,956		$	108,843		$	196,300		$	155,157
	Cement intersegment sales, which are to the ready mixed concrete product line in the West Group, was $22,061,000 for the three and nine months ended September 30, 2014.
			September 30,			December 31,			September 30,
			2014			2013			2013
			(Dollars in Thousands)
	Assets employed:
	Mid-America Group		$	1,313,472		$	1,242,394		$	1,270,025
	Southeast Group			604,261			611,906			628,805
	West Group			1,897,626			1,030,599			1,062,186
	Total Aggregates Business			3,815,359			2,884,899			2,961,016
	Cement			3,038,802			—			—
	Specialty Products			150,068			154,024			153,334
	Corporate			334,629			220,903			222,755
	Total		$	7,338,858		$	3,259,826		$	3,337,105
	The Aggregates business includes the aggregates product line and aggregates-related downstream product lines, which include asphalt, ready mixed concrete and road paving product lines. All aggregates-related downstream product lines reside in the West Group. The following tables provide net sales and gross profit by product line for the Aggregates business, which are reconciled to consolidated amounts, as follows:
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2014			2013			2014			2013
			(Dollars in Thousands)
	Net sales:
	Aggregates		$	478,834		$	411,206		$	1,164,692		$	1,016,238
	Asphalt			26,873			23,787			59,998			52,231
	Ready Mixed Concrete			183,715			41,765			274,103			103,347
	Road Paving			60,327			67,905			113,302			112,437
	Total Aggregates Business			749,749			544,663			1,612,095			1,284,253
	Cement			109,521			—			109,521			—
	Specialty Products			58,672			55,794			177,941			167,595
	Total		$	917,942		$	600,457		$	1,899,557		$	1,451,848
	Gross profit (loss):
	Aggregates		$	119,277		$	108,166		$	229,471		$	189,171
	Asphalt			7,356			7,322			10,799			9,770
	Ready Mixed Concrete			18,628			3,124			28,554			4,911
Road Paving			6,897			4,286			2,665			(285	)
Total Aggregates Business			152,158			122,898			271,489			203,567
Cement			24,194			—			24,194			—
Specialty Products			20,043			19,919			62,192			60,784
Corporate			(802	)		291			(845	)		(1,426	)
Total		$	195,593		$	143,108		$	357,030		$	262,925

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2014
Supplemental Cash Flow Information	'
	11	Supplemental Cash Flow Information
	The components of the change in other assets and liabilities, net, are as follows:
			Nine Months Ended
			September 30,
			2014			2013
			(Dollars in Thousands)
	Other current and noncurrent assets		$	3,998		$	(42	)
	Accrued salaries, benefits and payroll taxes			27,911			(1,307	)
	Accrued insurance and other taxes			10,510			5,761
	Accrued income taxes			7,096			18,369
	Accrued pension, postretirement and postemployment benefits			(2,136	)		(10,431	)
	Other current and noncurrent liabilities			(742	)		13,228
			$	46,637		$	25,578
	The increase in accrued salaries, benefits and payroll taxes is primarily attributable to the accrual for certain unpaid severance arrangements.
	Noncash investing and financing activities are as follows:
			Nine Months Ended
			September 30,
			2014			2013
			(Dollars in Thousands)
	Noncash investing and financing activities:
	Acquisition of assets through capital lease		$	7,788		$	—
	Acquisition of land through seller financing			1,500			—
	Acquisition of land through asset swap			2,091			—
	Acquisition of TXI assets and liabilities assumed through issuances of common stock and options (See Note 2)			2,691,986			—

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Organization	'
	Organization
	Martin Marietta (the “Corporation”) is engaged principally in the construction aggregates business. The Corporation’s aggregates product line includes crushed stone, sand and gravel, and is used for construction of highways and other infrastructure projects, and in the nonresidential and residential construction industries. Aggregates products are also used in the railroad, agricultural, utility and environmental industries. These aggregates products, along with the Corporation’s aggregates-related downstream product lines, which include asphalt products, ready mixed concrete and road paving construction services, are sold and shipped from a network of approximately 420 quarries, distribution facilities and plants to customers in 30 states, Canada, the Bahamas and the Caribbean Islands. The aggregates and aggregates-related downstream product lines are reported collectively as the “Aggregates business”.
	Effective January 1, 2014, the Corporation made minor changes to the operations and management reporting structure of its Aggregates business, resulting in an immaterial change to its reportable segments. The Corporation currently conducts the Aggregates business through three reportable segments: the Mid-America Group, the Southeast Group and the West Group.
	AGGREGATES BUSINESS
	Reportable Segments	Mid-America Group		Southeast Group	West Group
	Operating Locations	Indiana, Iowa,		Alabama, Florida,	Arkansas,
		northern Kansas,		Georgia,	Colorado,
		Kentucky,		Mississippi,	southern Kansas,
		Maryland,		Tennessee, Nova	Louisiana,
		Minnesota,		Scotia and the	western Nebraska,
		Missouri,		Bahamas	Nevada,
		eastern Nebraska,			Oklahoma, Texas,
		North Carolina,			Utah and
		Ohio, South Carolina,			Wyoming
		Virginia,
		Washington and
		West Virginia
	The Corporation has a Cement segment, which is comprised of cement operations acquired from Texas Industries, Inc. (“TXI”) with production facilities located in Midlothian, Texas, south of Dallas/Fort Worth; Hunter Texas, south of San Antonio; and Oro Grande, near Los Angeles, California. See Note 2 for additional information on the acquisition. The cement business produces Portland and specialty cements, such as masonry and oil well cements. Similar to the Aggregates business, cement is used in infrastructure projects, nonresidential and residential construction, and the railroad, agricultural, utility and environmental industries. The limestone reserves used as a raw material are located on owned property adjacent to each of the plants. The Corporation also operates cement terminals, a packaging facility at the Crestmore plant near Riverside, California, and its Portland cement grinding facility on an as needed basis.
	The Corporation has a Specialty Products segment with manufacturing facilities in Manistee, Michigan and Woodville, Ohio. The Specialty Products segment produces magnesia-based chemicals products used in industrial, agricultural and environmental applications and dolomitic lime sold primarily to customers in the steel industry.
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited consolidated financial statements of the Corporation have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to the Quarterly Report on Form 10-Q and in Article 10 of Regulation S-X. Other than the adoption of a new accounting standard (see page 9), the Corporation has continued to follow the accounting policies set forth in the audited consolidated financial statements and related notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2013. In the opinion of management, the interim consolidated financial information provided herein reflects all adjustments, consisting of normal recurring accruals, necessary for a fair presentation of the results of operations, financial position and cash flows for the interim periods. The consolidated results of operations for the three and nine months ended September 30, 2014 are not indicative of the results expected for other interim periods or the full year. The consolidated balance sheet at December 31, 2013 has been derived from the audited consolidated financial statements at that date but does not include all of the information and notes required by generally accepted accounting principles for complete financial statements. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2013.
Early Adoption of New Accounting Standard	'
	Early Adoption of New Accounting Standard
	Effective January 1, 2014, the Corporation early adopted the Financial Accounting Standard Board’s (the “FASB”) final guidance on reporting discontinued operations. The guidance is to be applied prospectively and redefines discontinued operations to be either 1) a component of an entity or group of components that has been disposed of or is classified as held for sale that represents a strategic shift that has or will have a major effect on an entity’s operations and financial results or 2) a business that, upon acquisition, meets the criteria to be classified as held for sale. The adoption of the accounting standard did not have any effect on the Corporation’s financial position or results of operations.
Revenue Recognition Standard	'
	Revenue Recognition Standard
	The FASB issued an accounting standard update that amends the accounting guidance on revenue recognition. The new standard intends to provide a more robust framework for addressing revenue issues, improve comparability of revenue recognition practices and improve disclosure requirements. The new standard is effective for interim and annual reporting periods beginning after December 15, 2016 and can be applied on a full retrospective or modified retrospective approach. The Corporation is currently evaluating the impact of the provisions of the new standard, and at this time does not expect the impact to be material to its results of operations.
Reclassifications	'
	Reclassifications
	Prior-year segment information for the Aggregates business presented in Note 10 has been reclassified to conform to the presentation of the Corporation’s current reportable segments. In addition, certain other reclassifications have been made to prior year amounts to conform to the current year presentation.
Consolidated Comprehensive Earnings/Loss and Accumulated Other Comprehensive Loss	'
	Consolidated Comprehensive Earnings/Loss and Accumulated Other Comprehensive Loss
	Consolidated comprehensive earnings/loss for the Corporation consist of consolidated net earnings or loss; adjustments for the funded status of pension and postretirement benefit plans; foreign currency translation adjustments; and the amortization of the value of terminated forward starting interest rate swap agreements into interest expense, and are presented in the Corporation’s consolidated statements of earnings and comprehensive earnings.
	Comprehensive earnings attributable to Martin Marietta is as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net earnings attributable to Martin Marietta	$	53,743		$	71,836		$	91,646		$	85,304
	Other comprehensive (loss) earnings, net of tax		(1,140	)		3,548			833			3,459
	Comprehensive earnings attributable to Martin Marietta	$	52,603		$	75,384		$	92,479		$	88,763
	Comprehensive earnings (loss) attributable to noncontrolling interests, consisting of net earnings or loss 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,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net earnings (loss) attributable to noncontrolling interests	$	91		$	202		$	(1,341	)	$	(1,028	)
	Other comprehensive earnings, net of tax		2			3			4			8
	Comprehensive earnings (loss) attributable to noncontrolling interests	$	93		$	205		$	(1,337	)	$	(1,020	)
	Accumulated other comprehensive loss consists of unrealized gains and losses related to the funded status of pension and postretirement benefit plans; foreign currency translation; and the unamortized value of terminated forward starting interest rate swap agreements, and is presented on the Corporation’s consolidated balance sheets. Changes in accumulated other comprehensive loss, net of tax, are as follows:
		(Dollars in Thousands)
		Pension and			Foreign			Unamortized			Accumulated
		Postretirement			Currency			Value of			Other
		Benefit Plans						Terminated			Comprehensive
								Forward			Loss
								Starting
								Interest Rate
								Swap
		Three Months Ended September 30, 2014
	Balance at beginning of period	$	(44,685	)	$	5,658		$	(3,114	)	$	(42,141	)
	Other comprehensive loss before reclassifications, net of tax		—			(1,466	)		—			(1,466	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax		146			—			180			326
	Other comprehensive earnings (loss), net of tax		146			(1,466	)		180			(1,140	)
	Balance at end of period	$	(44,539	)	$	4,192		$	(2,934	)	$	(43,281	)
		Three Months Ended September 30, 2013
	Balance at beginning of period	$	(106,603	)	$	4,153		$	(3,808	)	$	(106,258	)
	Other comprehensive earnings before reclassifications, net of tax		—			993			—			993
	Amounts reclassified from accumulated other comprehensive loss, net of tax		2,387			—			168			2,555
	Other comprehensive earnings, net of tax		2,387			993			168			3,548
	Balance at end of period	$	(104,216	)	$	5,146		$	(3,640	)	$	(102,710	)
		(Dollars in Thousands)
		Pension and			Foreign			Unamortized			Accumulated
		Postretirement			Currency			Value of			Other
		Benefit Plans						Terminated			Comprehensive
								Forward			Loss
								Starting
								Interest Rate
								Swap
		Nine Months Ended September 30, 2014
	Balance at beginning of period	$	(44,549	)	$	3,902		$	(3,467	)	$	(44,114	)
	Other comprehensive (loss ) earnings before reclassifications, net of tax		(431	)		290			—			(141	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax		441			—			533			974
	Other comprehensive earnings, net of tax		10			290			533			833
	Balance at end of period	$	(44,539	)	$	4,192		$	(2,934	)	$	(43,281	)
		Nine Months Ended September 30, 2013
	Balance at beginning of period	$	(108,189	)	$	6,157		$	(4,137	)	$	(106,169	)
	Other comprehensive loss before reclassifications, net of tax		(2,312	)		(1,011	)		—			(3,323	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax		6,285			—			497			6,782
	Other comprehensive earnings (loss), net of tax		3,973			(1,011	)		497			3,459
	Balance at end of period	$	(104,216	)	$	5,146		$	(3,640	)	$	(102,710	)
	The other comprehensive loss before reclassifications for pension and postretirement benefit plans is net of tax of $280,000 and $1,514,000 for the nine months ended September 30, 2014 and 2013, respectively.
	Changes in net noncurrent deferred tax assets recorded in accumulated other comprehensive loss are as follows:
		(Dollars in Thousands)
		Pension and			Unamortized Value			Net Noncurrent
Postretirement		of Terminated			Deferred Tax
Benefit Plans		Forward Starting			Assets
		Interest Rate Swap
	Three Months Ended September 30, 2014
Balance at beginning of period	$	29,287		$	2,039		$	31,326
Tax effect of other comprehensive earnings		(96	)		(120	)		(216	)
Balance at end of period	$	29,191		$	1,919		$	31,110
	Three Months Ended September 30, 2013
Balance at beginning of period	$	69,842		$	2,492		$	72,334
Tax effect of other comprehensive earnings		(1,566	)		(111	)		(1,677	)
Balance at end of period	$	68,276		$	2,381		$	70,657
	Nine Months Ended September 30, 2014
Balance at beginning of period	$	29,198		$	2,269		$	31,467
Tax effect of other comprehensive earnings		(7	)		(350	)		(357	)
Balance at end of period	$	29,191		$	1,919		$	31,110
	Nine Months Ended September 30, 2013
Balance at beginning of period	$	70,881		$	2,707		$	73,588
Tax effect of other comprehensive earnings		(2,605	)		(326	)		(2,931	)
Balance at end of period	$	68,276		$	2,381		$	70,657
Reclassifications out of accumulated other comprehensive loss are as follows:
	Three Months Ended						Nine Months Ended						Affected line items in
	September 30,						September 30,
	2014			2013			2014			2013			the consolidated
													financial statements
	(Dollars in Thousands)
Pension and postretirement benefit plans Settlement expense	$	—		$	729		$	—		$	729
Amortization of:
Prior service credit		(703	)		(702	)		(2,107	)		(2,104	)
Actuarial loss		945			3,926			2,835			11,779
		242			3,953			728			10,404		Cost of sales;
													Selling, general & administrative expenses
Tax effect		(96	)		(1,566	)		(287	)		(4,119	)	Deferred income taxes
	$	146		$	2,387		$	441		$	6,285
Unamortized value of terminated forward starting interest rate swap
Additional interest expense	$	300		$	279		$	883		$	823		Interest expense
Tax effect		(120	)		(111	)		(350	)		(326	)	Deferred income taxes
	$	180		$	168		$	533		$	497
Earnings per Common Share	'
	Earnings per Common Share
	The numerator for basic and diluted earnings per common share is net earnings/loss attributable to Martin Marietta reduced by dividends and undistributed earnings attributable to the Corporation’s unvested restricted stock awards and incentive stock awards. If there is a net loss, no amount of the undistributed loss is attributed to unvested participating securities. The denominator for basic earnings per common share is the weighted-average number of common shares outstanding during the period. Diluted earnings per common share are computed assuming that the weighted-average number of common shares is increased by the conversion, using the treasury stock method, of awards to be issued to employees and nonemployee members of the Corporation’s Board of Directors under certain stock-based compensation arrangements if the conversion is dilutive. For the three and nine months ended September 30, 2014 and 2013, the diluted per-share computations reflect a change in the number of common shares outstanding to include the number of additional shares that would have been outstanding if the potentially dilutive common shares had been issued.
	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,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net earnings from continuing operations attributable to Martin Marietta	$	53,812		$	72,107		$	91,786		$	85,758
	Less: Distributed and undistributed earnings attributable to unvested awards		213			265			372			374
	Basic and diluted net earnings available to common shareholders from continuing operations attributable to Martin Marietta		53,599			71,842			91,414			85,384
	Basic and diluted net loss available to common shareholders from discontinued operations		(69	)		(271	)		(140	)		(454	)
	Basic and diluted net earnings available to common shareholders attributable to Martin Marietta	$	53,530		$	71,571		$	91,274		$	84,930
	Basic weighted-average common shares outstanding		67,086			46,244			53,342			46,134
	Effect of dilutive employee and director awards		409			105			217			127
	Diluted weighted-average common shares outstanding		67,495			46,349			53,559			46,261

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2014
Changes in Accumulated Other Comprehensive Earnings, Net of Tax	'
	Changes in accumulated other comprehensive loss, net of tax, are as follows:
		(Dollars in Thousands)
		Pension and			Foreign			Unamortized			Accumulated
		Postretirement			Currency			Value of			Other
		Benefit Plans						Terminated			Comprehensive
								Forward			Loss
								Starting
								Interest Rate
								Swap
		Three Months Ended September 30, 2014
	Balance at beginning of period	$	(44,685	)	$	5,658		$	(3,114	)	$	(42,141	)
	Other comprehensive loss before reclassifications, net of tax		—			(1,466	)		—			(1,466	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax		146			—			180			326
	Other comprehensive earnings (loss), net of tax		146			(1,466	)		180			(1,140	)
	Balance at end of period	$	(44,539	)	$	4,192		$	(2,934	)	$	(43,281	)
		Three Months Ended September 30, 2013
	Balance at beginning of period	$	(106,603	)	$	4,153		$	(3,808	)	$	(106,258	)
	Other comprehensive earnings before reclassifications, net of tax		—			993			—			993
	Amounts reclassified from accumulated other comprehensive loss, net of tax		2,387			—			168			2,555
	Other comprehensive earnings, net of tax		2,387			993			168			3,548
	Balance at end of period	$	(104,216	)	$	5,146		$	(3,640	)	$	(102,710	)
		(Dollars in Thousands)
		Pension and			Foreign			Unamortized			Accumulated
		Postretirement			Currency			Value of			Other
		Benefit Plans						Terminated			Comprehensive
								Forward			Loss
								Starting
								Interest Rate
								Swap
		Nine Months Ended September 30, 2014
	Balance at beginning of period	$	(44,549	)	$	3,902		$	(3,467	)	$	(44,114	)
	Other comprehensive (loss ) earnings before reclassifications, net of tax		(431	)		290			—			(141	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax		441			—			533			974
	Other comprehensive earnings, net of tax		10			290			533			833
	Balance at end of period	$	(44,539	)	$	4,192		$	(2,934	)	$	(43,281	)
		Nine Months Ended September 30, 2013
	Balance at beginning of period	$	(108,189	)	$	6,157		$	(4,137	)	$	(106,169	)
	Other comprehensive loss before reclassifications, net of tax		(2,312	)		(1,011	)		—			(3,323	)
	Amounts reclassified from accumulated other comprehensive loss, net of tax		6,285			—			497			6,782
	Other comprehensive earnings (loss), net of tax		3,973			(1,011	)		497			3,459
	Balance at end of period	$	(104,216	)	$	5,146		$	(3,640	)	$	(102,710	)
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			Unamortized Value			Net Noncurrent
		Postretirement			of Terminated			Deferred Tax
		Benefit Plans			Forward Starting			Assets
					Interest Rate Swap
		Three Months Ended September 30, 2014
	Balance at beginning of period	$	29,287		$	2,039		$	31,326
	Tax effect of other comprehensive earnings		(96	)		(120	)		(216	)
	Balance at end of period	$	29,191		$	1,919		$	31,110
		Three Months Ended September 30, 2013
	Balance at beginning of period	$	69,842		$	2,492		$	72,334
	Tax effect of other comprehensive earnings		(1,566	)		(111	)		(1,677	)
	Balance at end of period	$	68,276		$	2,381		$	70,657
		Nine Months Ended September 30, 2014
	Balance at beginning of period	$	29,198		$	2,269		$	31,467
	Tax effect of other comprehensive earnings		(7	)		(350	)		(357	)
	Balance at end of period	$	29,191		$	1,919		$	31,110
		Nine Months Ended September 30, 2013
	Balance at beginning of period	$	70,881		$	2,707		$	73,588
	Tax effect of other comprehensive earnings		(2,605	)		(326	)		(2,931	)
	Balance at end of period	$	68,276		$	2,381		$	70,657
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
		September 30,						September 30,
		2014			2013			2014			2013			the consolidated
														financial statements
		(Dollars in Thousands)
	Pension and postretirement benefit plans
	Settlement expense	$	—		$	729		$	—		$	729
	Amortization of:
	Prior service credit		(703	)		(702	)		(2,107	)		(2,104	)
	Actuarial loss		945			3,926			2,835			11,779
			242			3,953			728			10,404		Cost of sales;
														Selling, general & administrative expenses
	Tax effect		(96	)		(1,566	)		(287	)		(4,119	)	Deferred income taxes
		$	146		$	2,387		$	441		$	6,285
	Unamortized value of terminated forward starting interest rate swap
	Additional interest expense	$	300		$	279		$	883		$	823		Interest expense
	Tax effect		(120	)		(111	)		(350	)		(326	)	Deferred income taxes
		$	180		$	168		$	533		$	497
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,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net earnings from continuing operations attributable to Martin Marietta	$	53,812		$	72,107		$	91,786		$	85,758
	Less: Distributed and undistributed earnings attributable to unvested awards		213			265			372			374
	Basic and diluted net earnings available to common shareholders from continuing operations attributable to Martin Marietta		53,599			71,842			91,414			85,384
	Basic and diluted net loss available to common shareholders from discontinued operations		(69	)		(271	)		(140	)		(454	)
	Basic and diluted net earnings available to common shareholders attributable to Martin Marietta	$	53,530		$	71,571		$	91,274		$	84,930
	Basic weighted-average common shares outstanding		67,086			46,244			53,342			46,134
	Effect of dilutive employee and director awards		409			105			217			127
	Diluted weighted-average common shares outstanding		67,495			46,349			53,559			46,261
Parent	'
Comprehensive Earnings (Loss) Attributable	'
	Comprehensive earnings attributable to Martin Marietta is as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net earnings attributable to Martin Marietta	$	53,743		$	71,836		$	91,646		$	85,304
	Other comprehensive (loss) earnings, net of tax		(1,140	)		3,548			833			3,459
	Comprehensive earnings attributable to Martin Marietta	$	52,603		$	75,384		$	92,479		$	88,763
Noncontrolling Interest	'
Comprehensive Earnings (Loss) Attributable	'
	Comprehensive earnings (loss) attributable to noncontrolling interests, consisting of net earnings or loss 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,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net earnings (loss) attributable to noncontrolling interests	$	91		$	202		$	(1,341	)	$	(1,028	)
	Other comprehensive earnings, net of tax		2			3			4			8
	Comprehensive earnings (loss) attributable to noncontrolling interests	$	93		$	205		$	(1,337	)	$	(1,020	)

Business_Combinations_and_Dive1

Business Combinations and Divestitures (Tables)	9 Months Ended
	Sep. 30, 2014
Summary of Estimated Fair values of Assets Acquired and Liabilities Assumed	'
	The following is a summary of the estimated fair values of the assets acquired and the liabilities assumed (dollars in thousands).
	Assets:
	Cash and cash equivalents	$	59,887
	Receivables		161,437
	Inventory		132,972
	Other current assets		56,246
	Property, plant and equipment		1,608,305
	Real estate and other investments		59,584
	Intangible assets, other than goodwill		559,327
	Other noncurrent assets		5,367
	Goodwill		1,457,043
	Total assets		4,100,168
	Liabilities:
	Accounts payable and accrued expenses		259,723
	Notes and contracts payable and capital leases		745,217
	Deferred income tax liabilities		338,294
	Total liabilities		1,343,234
	Total consideration	$	2,756,934
Pro Forma Financial Information	'
	The pro forma financial information as presented below is for informational purposes only and is not indicative of the results of operations that would have been achieved if the acquisitions had taken place at the beginning of fiscal year 2013.
		Three Months Ended		Nine Months Ended
		September 30,		September 30,
		2013		2014		2013
		(Dollars in Thousands)
	Net sales	$	802,575	$	2,309,104	$	1,962,216
	Earnings from continuing operations attributable to controlling interest	$	67,930	$	106,928	$	83,661

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Changes in Goodwill	'
	The following table shows the changes in goodwill by reportable segment and in total:
		Mid-America		Southeast			West			Cement		Total
		Group		Group			Group
	(Dollars in Thousands)	Nine Months Ended September 30, 2014
	Balance at January 1, 2014	$	263,967	$	50,346		$	302,308		$	—	$	616,621
	Organizational changes		18,150					(18,150	)				—
	Acquisitions		—		—			614,224			842,819		1,457,043
	Amounts allocated to divestitures		—		—			(30,344	)		—		(30,344	)
	Balance at September 30, 2014	$	282,117	$	50,346		$	868,038		$	842,819	$	2,043,320
		Year Ended December 31, 2013
	Balance at January 1, 2013	$	263,868	$	50,001		$	302,335		$	—	$	616,204
	Acquisitions		99		345						—		444
	Adjustments to purchase price allocations		—		—			(27	)		—		(27	)
	Balance at December 31, 2013	$	263,967	$	50,346		$	302,308		$	—	$	616,621
Intangible Assets Subject to Amortization	'
	Intangible assets subject to amortization consist of the following:
		Gross		Accumulated			Net
		Amount		Amortization			Balance
	(Dollars in Thousands)	September 30, 2014
	Noncompetition agreements	$	6,274	$	(5,874	)	$	400
	Customer relationships		36,610		(6,824	)		29,786
	Operating permits		498,685		(3,551	)		495,134
	Use rights and other		15,386		(6,669	)		8,717
	Trade name		12,800		(572	)		12,228
	Total	$	569,755	$	(23,490	)	$	546,265
		31-Dec-13
	Noncompetition agreements	$	6,274	$	(5,583	)	$	691
	Customer relationships		20,660		(6,160	)		14,500
	Operating permits		6,800		(1,394	)		5,406
	Use rights and other		10,115		(6,156	)		3,959
	Total	$	43,849	$	(19,293	)	$	24,556
Intangible Assets Deemed to Indefinite Life and Not Being Amortized	'
	Intangible assets deemed to have an indefinite life and not being amortized consist of the following:
		Aggregates		Cement			Specialty			Total
		Business					Products
	(Dollars in Thousands)	September 30, 2014
	Operating permits	$	6,600	$	—		$	—		$	6,600
	Use rights		9,385		20,027			—			29,412
	Trade name		80		14,300			2,565			16,945
	Total	$	16,065	$	34,327		$	2,565		$	52,957
		31-Dec-13
	Operating permits	$	11,635	$	—		$	—		$	11,635
	Use rights		9,835		—			—			9,835
	Trade name		—		—			2,565			2,565
	Total	$	21,470	$	—		$	2,565		$	24,035
Schedule of Acquired Intangibles	'
	The Corporation acquired $559,327,000 of intangibles from the TXI acquisition, which consists of the following:
	(Dollars in Thousands)	Amount		Weighted-average
				amortization period
	Subject to amortization:
	Customer relationships	$	20,150	12.0 years
	Operating permits		487,150	87.3 years
	Use rights and other		4,820	8.2 years
	Trade name		12,800	6.0 years
		$	524,920	81.7 years
	Not subject to amortization:
	Use rights	$	20,027	N/A
	Trade name		14,380
			34,407
	Total	$	559,327
Estimated Amortization Expense of Intangible Assets	'
	The estimated amortization expense for intangible assets for the three months ending December 31, 2014 and for each of the next five years and thereafter is as follows:
	(Dollars in Thousands)
	Remainder of 2014	$	3,773
	2015		14,453
	2016		14,149
	2017		14,009
	2018		13,118
	2019		12,192
	Thereafter		474,571
	Total	$	546,265

Inventories_Net_Tables

Inventories, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Schedule of Inventories Net	'
		September 30,			December 31,			September 30,
		2014			2013			2013
		(Dollars in Thousands)
	Finished products	$	397,684		$	368,334		$	366,558
	Products in process and raw materials		58,678			16,077			19,924
	Supplies and expendable parts		127,319			61,922			61,441
			583,681			446,333			447,923
	Less: Allowances		(108,388	)		(99,026	)		(97,485	)
	Total	$	475,293		$	347,307		$	350,438

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Long-Term Debt	'
		September 30,			December 31,			September 30,
		2014			2013			2013
		(Dollars in Thousands)
	6.6% Senior Notes, due 2018	$	299,063		$	298,893		$	298,837
	7% Debentures, due 2025		124,493			124,471			124,464
	6.25% Senior Notes, due 2037		228,175			228,148			228,139
	4.25% Senior Notes, due 2024		395,211			—			—
	Floating Rate Notes, due 2017, interest rate of 1.34% at September 30, 2014		298,760			—			—
	Term Loan Facility, due 2018, interest rate of 1.65% at September 30, 2014; 1.67% at December 31, 2013; and 2.20% at September 30, 2013		239,304			248,441			240,000
	Revolving Facility, interest rate of 1.89% at September 30, 2013		—			—			70,000
	Trade Receivable Facility, interest rate of 0.76% at September 30, 2014; 0.77% at December 31, 2013; and 0.79% at September 30, 2013		30,000			130,000			150,000
	Other notes		3,269			968			1,921
	Total debt		1,618,275			1,030,921			1,113,361
	Less: Current maturities		(14,331	)		(12,403	)		(6,169	)
	Long-term debt	$	1,603,944		$	1,018,518		$	1,107,192

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2014
Schedule of Estimated Effective Income Tax Rate	'
		Nine Months Ended September 30,
		2014			2013
	Estimated effective income tax rate:
	Continuing operations		39.7	%		25.9	%
	Discontinued operations		27.6	%		35.6	%
	Consolidated overall		39.7	%		25.8	%
Unrecognized Tax Benefits Excluding Interest Correlative Effects and Indirect Benefits	'
	The Corporation’s unrecognized tax benefits, excluding interest, correlative effects and indirect benefits, are as follows:
		Nine Months Ended
		September 30, 2014
		(Dollars in Thousands)
	Unrecognized tax benefits at beginning of period	$	11,826
	Gross increases – tax positions in prior years		1,898
	Gross decreases – tax positions in prior years		(204	)
	Gross increases – tax positions in current year		1,418
	Gross increases as a result of lapse of statute of limitations		4,442
	Gross decreases as a result of lapse of statute of limitations		(6,314	)
	Increases – uncertain tax positions assumed in connection with an acquisition		5,963
	Unrecognized tax benefits at end of period	$	19,029

Pension_and_Postretirement_Ben1

Pension and Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2014
Schedule of Components of Net Periodic Benefit Cost	'
	The estimated components of the recorded net periodic benefit cost (credit) for pension and postretirement benefits are as follows:
		Three Months Ended September 30,
		Pension						Postretirement Benefits
		2014			2013			2014			2013
		(Dollars in Thousands)
	Service cost	$	4,996		$	4,030		$	57		$	57
	Interest cost		7,979			5,756			302			253
	Expected return on assets		(8,627	)		(6,668	)		—			—
	Amortization of:
	Prior service cost (credit)		111			112			(814	)		(814	)
	Actuarial loss (gain)		1,011			3,920			(66	)		6
	Settlement charge		—			729			—			—
	Termination benefit cost		13,680			—			—			—
	Net periodic benefit cost (credit)	$	19,150		$	7,879		$	(521	)	$	(498	)
		Nine Months Ended September 30,
		Pension						Postretirement Benefits
		2014			2013			2014			2013
		(Dollars in Thousands)
	Service cost	$	12,129		$	12,091		$	150		$	170
	Interest cost		20,952			17,268			861			760
	Expected return on assets		(24,030	)		(20,003	)		—			—
	Amortization of:
	Prior service cost (credit)		334			337			(2,441	)		(2,441	)
	Actuarial loss (gain)		3,034			11,760			(199	)		19
	Settlement charge		—			729			—			—
	Termination benefit cost		13,680			—			—			—
	Net periodic benefit cost (credit)	$	26,099		$	22,182		$	(1,629	)	$	(1,492	)

Business_Segments_Tables

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2014
Financial Data for Continuing Operation For Corporation's Reportable Business Segments	'
	The following tables display selected financial data for continuing operations for the Corporation’s reportable business segments. Corporate loss from operations primarily includes depreciation on capitalized interest, expenses for corporate administrative functions, business development and integration expenses, unallocated corporate expenses and other nonrecurring and/or non-operational adjustments. Intersegment sales represent net sales from one segment to another segment. Total revenues and net sales in the table below, as well as the consolidated statements of earnings and comprehensive earnings, do not include intersegment sales as these sales are eliminated.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Total revenues:
	Mid-America Group	$	271,096		$	255,737		$	627,331		$	592,794
	Southeast Group		73,217			69,490			208,205			185,676
	West Group		479,323			279,477			956,921			649,896
	Total Aggregates Business		823,636			604,704			1,792,457			1,428,366
	Cement		115,743			—			115,743			—
	Specialty Products		64,344			60,616			193,378			182,189
	Total	$	1,003,723		$	665,320		$	2,101,578		$	1,610,555
	Net sales:
	Mid-America Group	$	244,309		$	231,807		$	569,545		$	540,209
	Southeast Group		68,042			64,871			194,148			171,456
	West Group		437,398			247,985			848,402			572,588
	Total Aggregates Business		749,749			544,663			1,612,095			1,284,253
	Cement		109,521			—			109,521			—
	Specialty Products		58,672			55,794			177,941			167,595
	Total	$	917,942		$	600,457		$	1,899,557		$	1,451,848
	Earnings (Loss) from operations:
	Mid-America Group	$	71,185		$	67,162		$	116,703		$	100,915
	Southeast Group		329			(1,386	)		(7,084	)		(14,949	)
	West Group		92,115			31,559			125,069			39,829
	Total Aggregates Business		163,629			97,335			234,688			125,795
	Cement		18,278			—			18,278			—
	Specialty Products		17,697			17,267			54,976			53,071
	Corporate		(83,648	)		(5,759	)		(111,642	)		(23,709	)
	Total	$	115,956		$	108,843		$	196,300		$	155,157
Asset Employed for Continuing Operations for Corporations Reportable Business Segments	'
		September 30,			December 31,			September 30,
		2014			2013			2013
		(Dollars in Thousands)
	Assets employed:
	Mid-America Group	$	1,313,472		$	1,242,394		$	1,270,025
	Southeast Group		604,261			611,906			628,805
	West Group		1,897,626			1,030,599			1,062,186
	Total Aggregates Business		3,815,359			2,884,899			2,961,016
	Cement		3,038,802			—			—
	Specialty Products		150,068			154,024			153,334
	Corporate		334,629			220,903			222,755
	Total	$	7,338,858		$	3,259,826		$	3,337,105
Net Sales By Product Line	'
	The following tables provide net sales and gross profit by product line for the Aggregates business, which are reconciled to consolidated amounts, as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(Dollars in Thousands)
	Net sales:
	Aggregates	$	478,834		$	411,206		$	1,164,692		$	1,016,238
	Asphalt		26,873			23,787			59,998			52,231
	Ready Mixed Concrete		183,715			41,765			274,103			103,347
	Road Paving		60,327			67,905			113,302			112,437
	Total Aggregates Business		749,749			544,663			1,612,095			1,284,253
	Cement		109,521			—			109,521			—
	Specialty Products		58,672			55,794			177,941			167,595
	Total	$	917,942		$	600,457		$	1,899,557		$	1,451,848
	Gross profit (loss):
	Aggregates	$	119,277		$	108,166		$	229,471		$	189,171
	Asphalt		7,356			7,322			10,799			9,770
	Ready Mixed Concrete		18,628			3,124			28,554			4,911
	Road Paving		6,897			4,286			2,665			(285	)
	Total Aggregates Business		152,158			122,898			271,489			203,567
	Cement		24,194			—			24,194			—
	Specialty Products		20,043			19,919			62,192			60,784
	Corporate		(802	)		291			(845	)		(1,426	)
	Total	$	195,593		$	143,108		$	357,030		$	262,925

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2014
Components of Change in Other Assets and Liabilities, Net	'
	The components of the change in other assets and liabilities, net, are as follows:
		Nine Months Ended
		September 30,
		2014			2013
		(Dollars in Thousands)
	Other current and noncurrent assets	$	3,998		$	(42	)
	Accrued salaries, benefits and payroll taxes		27,911			(1,307	)
	Accrued insurance and other taxes		10,510			5,761
	Accrued income taxes		7,096			18,369
	Accrued pension, postretirement and postemployment benefits		(2,136	)		(10,431	)
	Other current and noncurrent liabilities		(742	)		13,228
		$	46,637		$	25,578
Schedule of Noncash Investing and Financing Activities	'
	Noncash investing and financing activities are as follows:
		Nine Months Ended
		September 30,
		2014			2013
		(Dollars in Thousands)
	Noncash investing and financing activities:
	Acquisition of assets through capital lease	$	7,788		$	—
	Acquisition of land through seller financing		1,500			—
	Acquisition of land through asset swap		2,091			—
	Acquisition of TXI assets and liabilities assumed through issuances of common stock and options (See Note 2)		2,691,986			—

Significant_Accounting_Policie3

Significant Accounting Policies - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
	State
	Facility
Significant Accounting Policies [Line Items]	'	'
Number of quarries distribution facilities and plants	420	'
Number of states with aggregates business sales by destination	30	'
Other comprehensive loss before reclassifications for pension and postretirement benefit plans, tax	$280,000	$1,514,000

Comprehensive_Earnings_Attribu

Comprehensive Earnings Attributable to Martin Marietta Materials Incorporated (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Comprehensive Income (Loss)	'	'	'	'
Net earnings attributable to Martin Marietta	$53,743	$71,836	$91,646	$85,304
Other comprehensive (loss) earnings, net of tax	-1,140	3,548	833	3,459
Comprehensive earnings attributable to Martin Marietta	$52,603	$75,384	$92,479	$88,763

Comprehensive_Earnings_Loss_At

Comprehensive Earnings (Loss) Attributable to Noncontrolling Interests (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Comprehensive Income (Loss)	'	'	'	'
Net earnings (loss) attributable to noncontrolling interests	$91	$202	($1,341)	($1,028)
Other comprehensive earnings, net of tax	2	3	4	8
Comprehensive earnings (loss) attributable to noncontrolling interests	$93	$205	($1,337)	($1,020)

Changes_in_Accumulated_Other_C

Changes in Accumulated Other Comprehensive Earnings, Net of Tax (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss)	'	'	'	'
Balance at beginning of period	($42,141)	($106,258)	($44,114)	($106,169)
Other comprehensive (loss) earnings before reclassifications, net of tax	-1,466	993	-141	-3,323
Amounts reclassified from accumulated other comprehensive loss, net of tax	326	2,555	974	6,782
Other comprehensive earnings (loss), net of tax	-1,140	3,548	833	3,459
Balance at end of period	-43,281	-102,710	-43,281	-102,710
Pension and Postretirement Benefit Plans	'	'	'	'
Accumulated Other Comprehensive Income (Loss)	'	'	'	'
Balance at beginning of period	-44,685	-106,603	-44,549	-108,189
Other comprehensive (loss) earnings before reclassifications, net of tax	'	'	-431	-2,312
Amounts reclassified from accumulated other comprehensive loss, net of tax	146	2,387	441	6,285
Other comprehensive earnings (loss), net of tax	146	2,387	10	3,973
Balance at end of period	-44,539	-104,216	-44,539	-104,216
Foreign Currency	'	'	'	'
Accumulated Other Comprehensive Income (Loss)	'	'	'	'
Balance at beginning of period	5,658	4,153	3,902	6,157
Other comprehensive (loss) earnings before reclassifications, net of tax	-1,466	993	290	-1,011
Other comprehensive earnings (loss), net of tax	-1,466	993	290	-1,011
Balance at end of period	4,192	5,146	4,192	5,146
Unamortized Value of Terminated Forward Starting Interest Rate Swap	'	'	'	'
Accumulated Other Comprehensive Income (Loss)	'	'	'	'
Balance at beginning of period	-3,114	-3,808	-3,467	-4,137
Amounts reclassified from accumulated other comprehensive loss, net of tax	180	168	533	497
Other comprehensive earnings (loss), net of tax	180	168	533	497
Balance at end of period	($2,934)	($3,640)	($2,934)	($3,640)

Noncurrent_Deferred_Tax_Assets

Noncurrent Deferred Tax Assets Recorded in Accumulated Other Comprehensive Loss (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss)	'	'	'	'
Balance at beginning of period, Pension and Postretirement Benefit Plans	$29,287	$69,842	$29,198	$70,881
Other comprehensive earnings, tax effect, Pension and Postretirement Benefit Plans	-96	-1,566	-7	-2,605
Balance at end of period, Pension and Postretirement Benefit Plans	29,191	68,276	29,191	68,276
Balance at beginning of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	2,039	2,492	2,269	2,707
Other comprehensive earnings, tax effect, Unamortized Value of Terminated Forward Starting Interest Rate Swap	-120	-111	-350	-326
Balance at end of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	1,919	2,381	1,919	2,381
Balance at beginning of period, Net Non current Deferred Tax Assets	31,326	72,334	31,467	73,588
Other comprehensive earnings, tax effect, Net Non current Deferred Tax Assets	-216	-1,677	-357	-2,931
Balance at end of period, Net Non current Deferred Tax Assets	$31,110	$70,657	$31,110	$70,657

Reclassifications_Out_of_Accum

Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Tax effect	$96	$1,566	$7	$2,605
Earnings from Continuing Operations	53,903	72,309	90,445	84,730
Additional interest expense	-19,805	-13,518	-44,954	-40,633
Tax effect	120	111	350	326
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefit Plans	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Settlement expense	'	729	'	729
Prior service credit	-703	-702	-2,107	-2,104
Actuarial loss	945	3,926	2,835	11,779
Earnings from Continuing Operations	146	2,387	441	6,285
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefit Plans | Deferred Income Taxes	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Tax effect	-96	-1,566	-287	-4,119
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefit Plans | Cost of sale; Selling, General & Administrative Expenses	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Total reclassifications out of accumulated other comprehensive loss before taxes	242	3,953	728	10,404
Reclassification out of Accumulated Other Comprehensive Income | Unamortized Value of Terminated Forward Starting Interest Rate Swap	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Earnings from Continuing Operations	180	168	533	497
Additional interest expense	300	279	883	823
Reclassification out of Accumulated Other Comprehensive Income | Unamortized Value of Terminated Forward Starting Interest Rate Swap | Deferred Income Taxes	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Tax effect	($120)	($111)	($350)	($326)

Basic_and_Diluted_Earnings_Per

Basic and Diluted Earnings Per Common Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule of Earnings Per Share, Basic and Diluted, by Common Class	'	'	'	'
Net earnings from continuing operations attributable to Martin Marietta	$53,812	$72,107	$91,786	$85,758
Less: Distributed and undistributed earnings attributable to unvested awards	213	265	372	374
Basic and diluted net earnings available to common shareholders from continuing operations attributable to Martin Marietta	53,599	71,842	91,414	85,384
Basic and diluted net loss available to common shareholders from discontinued operations	-69	-271	-140	-454
Basic and diluted net earnings available to common shareholders attributable to Martin Marietta	$53,530	$71,571	$91,274	$84,930
Basic weighted-average common shares outstanding	67,086	46,244	53,342	46,134
Effect of dilutive employee and director awards	409	105	217	127
Diluted weighted-average common shares outstanding	67,495	46,349	53,559	46,261

Acquisitions_and_Divestitures_

Acquisitions and Divestitures - Additional Information (Detail) (USD $)	0 Months Ended	9 Months Ended	0 Months Ended		3 Months Ended	9 Months Ended
	Aug. 15, 2014	Sep. 30, 2014	Jul. 01, 2014	Jan. 27, 2014	Sep. 30, 2014	Sep. 30, 2014	Jul. 01, 2014
		JointVentures	Texas Industries Inc.	Texas Industries Inc.	Texas Industries Inc.	Texas Industries Inc.	Texas Industries Inc.
Acquisitions And Divestitures [Line Items]	'	'	'	'	'	'	'
Number of shares issued per single share	'	'	'	0.7	'	'	'
Common shares issued to former shareholders	'	'	'	20,309,000	'	'	'
Stock price	'	'	'	'	'	'	$132
Aggregate value of common shares issued to former shareholders	'	'	'	'	'	'	$2,680,788,000
Stock options and stock appreciation rights converted into stock awards	'	'	71,085,000	'	'	'	'
Total consideration transferred	'	'	'	'	2,756,934,000	2,756,934,000	2,756,934,000
Total revenue from operations included in the consolidated earnings statements	'	'	'	'	'	287,587,000	'
Total revenue from operations included in the consolidated earnings statements	'	'	'	'	'	18,755,000	'
Business development expenses	'	'	'	'	73,968,000	73,968,000	'
Acquisition integration expenses	'	'	'	'	88,959,000	88,959,000	'
Pretax gain on divestiture of business	47,904,000	'	'	'	'	'	'
Payment to acquire the remaining interest in the joint ventures	'	$19,480,000	'	'	'	'	'
Number of joint ventures	'	2	'	'	'	'	'

Summary_of_Estimated_Fair_valu

Summary of Estimated Fair values of Assets Acquired and Liabilities Assumed (Detail) (Texas Industries Inc., USD $)	Sep. 30, 2014	Jul. 01, 2014
In Thousands, unless otherwise specified
Texas Industries Inc.	'	'
Assets:	'	'
Cash and cash equivalents	$59,887	'
Receivables	161,437	'
Inventory	132,972	'
Other current assets	56,246	'
Property, plant and equipment	1,608,305	'
Real estate and other investments	59,584	'
Intangible assets, other than goodwill	559,327	'
Other noncurrent assets	5,367	'
Goodwill	1,457,043	'
Total assets	4,100,168	'
Liabilities:	'	'
Accounts payable and accrued expenses	259,723	'
Notes and contracts payable and capital leases	745,217	'
Deferred income tax liabilities	338,294	'
Total liabilities	1,343,234	'
Total consideration	$2,756,934	$2,756,934

Pro_Forma_Financial_Informatio

Pro Forma Financial Information (Detail) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition, Pro Forma Information [Line Items]	'	'	'
Net sales	$802,575	$2,309,104	$1,962,216
Earnings from continuing operations attributable to controlling interest	$67,930	$106,928	$83,661

Changes_in_Goodwill_Detail

Changes in Goodwill (Detail) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Goodwill	'	'	'
Balance at beginning of period	$616,621	$616,204	$616,634
Acquisitions	1,457,043	444	'
Amounts allocated to divestitures	-30,344	'	'
Adjustments to purchase price allocations	'	-27	'
Balance at end of period	2,043,320	616,621	616,634
Mid-America Group	'	'	'
Goodwill	'	'	'
Balance at beginning of period	263,967	263,868	'
Organizational changes	18,150	'	'
Acquisitions	'	99	'
Balance at end of period	282,117	263,967	'
Southeast Group	'	'	'
Goodwill	'	'	'
Balance at beginning of period	50,346	50,001	'
Acquisitions	'	345	'
Balance at end of period	50,346	50,346	'
West Group	'	'	'
Goodwill	'	'	'
Balance at beginning of period	302,308	302,335	'
Organizational changes	-18,150	'	'
Acquisitions	614,224	'	'
Amounts allocated to divestitures	-30,344	'	'
Adjustments to purchase price allocations	'	-27	'
Balance at end of period	868,038	302,308	'
Cement	'	'	'
Goodwill	'	'	'
Acquisitions	842,819	'	'
Balance at end of period	$842,819	'	'

Intangible_Assets_Subject_to_A

Intangible Assets Subject to Amortization (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Amount	$569,755	$43,849
Accumulated Amortization	-23,490	-19,293
Net Balance	546,265	24,556
Noncompetition agreements	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Amount	6,274	6,274
Accumulated Amortization	-5,874	-5,583
Net Balance	400	691
Customer Relationships	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Amount	36,610	20,660
Accumulated Amortization	-6,824	-6,160
Net Balance	29,786	14,500
Operating Permits	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Amount	498,685	6,800
Accumulated Amortization	-3,551	-1,394
Net Balance	495,134	5,406
Use Rights And Other	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Amount	15,386	10,115
Accumulated Amortization	-6,669	-6,156
Net Balance	8,717	3,959
Trade name	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Gross Amount	12,800	'
Accumulated Amortization	-572	'
Net Balance	$12,228	'

Intangible_Assets_Deemed_to_In

Intangible Assets Deemed to Indefinite Life and Not Being Amortized (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	$52,957	$24,035
Aggregates Business	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	16,065	21,470
Specialty Products	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	2,565	2,565
Cement	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	34,327	'
Operating Permits	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	6,600	11,635
Operating Permits | Aggregates Business	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	6,600	11,635
Use Rights	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	29,412	9,835
Use Rights | Aggregates Business	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	9,385	9,835
Use Rights | Cement	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	20,027	'
Trade name	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	16,945	2,565
Trade name | Aggregates Business	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	80	'
Trade name | Specialty Products	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	2,565	2,565
Trade name | Cement	'	'
Schedule Of Other Intangible Assets [Line Items]	'	'
Indefinite life intangible assets	$14,300	'

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Goodwill And Other Intangibles [Line Items]	'	'
Other intangibles acquired from the TXI acquisition	$559,327,000	'
Amortization expense of intangible assets	$5,516,000	$2,692,000

Schedule_of_Acquired_Intangibl

Schedule of Acquired Intangibles (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles subject to amortization	$524,920
Acquired intangibles not subject to amortization	34,407
Acquired Intangibles, total	559,327
Acquired Finite-lived Intangible Assets, Useful Life	'81 years 8 months 12 days
Use Rights	'
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles not subject to amortization	20,027
Trade name	'
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles not subject to amortization	14,380
Customer Relationships	'
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles subject to amortization	20,150
Acquired Finite-lived Intangible Assets, Useful Life	'12 years
Operating Permits	'
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles subject to amortization	487,150
Acquired Finite-lived Intangible Assets, Useful Life	'87 years 3 months 18 days
Use Rights And Other	'
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles subject to amortization	4,820
Acquired Finite-lived Intangible Assets, Useful Life	'8 years 2 months 12 days
Trade name	'
Acquisition Goodwill And Other Intangible Assets [Line Items]	'
Acquired intangibles subject to amortization	$12,800
Acquired Finite-lived Intangible Assets, Useful Life	'6 years

Estimated_Amortization_Expense

Estimated Amortization Expense of Intangible Assets (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Expected Amortization Expense [Line Items]	'	'
Remainder of 2014	$3,773	'
2015	14,453	'
2016	14,149	'
2017	14,009	'
2018	13,118	'
2019	12,192	'
Thereafter	474,571	'
Net Balance	$546,265	$24,556

Inventories_Net_Detail

Inventories Net (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified
Inventory Disclosure	'	'	'
Finished products	$397,684	$368,334	$366,558
Products in process and raw materials	58,678	16,077	19,924
Supplies and expendable parts	127,319	61,922	61,441
Inventories, Gross	583,681	446,333	447,923
Less: Allowances	-108,388	-99,026	-97,485
Total	$475,293	$347,307	$350,438

Long_Term_Debt_Detail

Long Term Debt (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Debt Instrument	'	'	'
Total debt	$1,618,275,000	$1,030,921,000	$1,113,361,000
Less: Current maturities	-14,331,000	-12,403,000	-6,169,000
Long-term debt	1,603,944,000	1,018,518,000	1,107,192,000
6.6% Senior Notes, Due 2018	'	'	'
Debt Instrument	'	'	'
Total debt	299,063,000	298,893,000	298,837,000
7% Debentures, Due 2025	'	'	'
Debt Instrument	'	'	'
Total debt	124,493,000	124,471,000	124,464,000
6.25% Senior Notes, Due 2037	'	'	'
Debt Instrument	'	'	'
Total debt	228,175,000	228,148,000	228,139,000
4.25% Senior Notes, Due 2024	'	'	'
Debt Instrument	'	'	'
Total debt	395,211	'	'
Floating Rate Notes, Due 2017	'	'	'
Debt Instrument	'	'	'
Total debt	298,760,000	'	'
Term Loan Facility, Due 2018	'	'	'
Debt Instrument	'	'	'
Total debt	239,304,000	248,441,000	240,000,000
Trade Receivable Credit Facility	'	'	'
Debt Instrument	'	'	'
Credit Facility	30,000,000	130,000,000	150,000,000
Other notes	'	'	'
Debt Instrument	'	'	'
Other notes	3,269,000	968,000	1,921,000
Revolving Facility	'	'	'
Debt Instrument	'	'	'
Credit Facility	'	'	$70,000,000

Long_Term_Debt_Parenthetical_D

Long Term Debt (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
6.6% Senior Notes, Due 2018	'	'	'
Debt Instrument	'	'	'
Maturity date	'2018	'	'
Interest rate on notes	6.60%	'	'
7% Debentures, Due 2025	'	'	'
Debt Instrument	'	'	'
Maturity date	'2025	'	'
Interest rate on notes	7.00%	'	'
6.25% Senior Notes, Due 2037	'	'	'
Debt Instrument	'	'	'
Maturity date	'2037	'	'
Interest rate on notes	6.25%	'	'
4.25% Senior Notes, Due 2024	'	'	'
Debt Instrument	'	'	'
Maturity date	'2024	'	'
Interest rate on notes	4.25%	'	'
Floating Rate Notes, Due 2017	'	'	'
Debt Instrument	'	'	'
Maturity date	'2017	'	'
Interest rate	1.34%	'	'
Term Loan Facility, Due 2018	'	'	'
Debt Instrument	'	'	'
Maturity date	'2018	'	'
Interest rate	1.65%	1.67%	2.20%
Trade Receivable Credit Facility	'	'	'
Debt Instrument	'	'	'
Credit Facility interest rate	0.76%	0.77%	0.79%
Revolving Facility	'	'	'
Debt Instrument	'	'	'
Credit Facility interest rate	'	'	1.89%

LongTerm_Debt_Additional_infor

Long-Term Debt - Additional information (Detail) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 23, 2014

Dec. 31, 2014

Jun. 23, 2014

Jun. 23, 2014

Jun. 23, 2014

Jun. 23, 2014

Jun. 23, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 23, 2014

Jun. 23, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Jul. 01, 2014

Dec. 31, 2013

Sep. 30, 2013

Jul. 01, 2014

Including Acquisition Bridge Debt

Excluding Acquisition Bridge Debt

Minimum

Texas Industries Inc.

Texas Industries Inc.

Texas Industries Inc.

Texas Industries Inc.

Texas Industries Inc.

9.25% Senior Notes due 2020

9.25% Senior Notes due 2020

Floating Rate Senior Notes due in 2017

Floating Rate Senior Notes due in 2017

Floating Rate Senior Notes due in 2017

6.6% Senior Notes, Due 2018

6.6% Senior Notes, Due 2018

6.6% Senior Notes, Due 2018

4.25% Senior Notes due 2024

4.25% Senior Notes due 2024

Revolving Facility

Revolving Facility

Term Loan Facility

Trade Receivable Credit Facility

Trade Receivable Credit Facility

Trade Receivable Credit Facility

Trade Receivable Credit Facility

Trade Receivable Credit Facility

Maximum

Maximum

Maximum

Texas Industries Inc.

Texas Industries Inc.

three-month LIBOR

Credit Agreement Amendment

Amended

Amended

Scenario Forecast

Amended

Amended

Amended

Debt Instrument

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior notes

$1,618,275,000

$1,113,361,000

$1,618,275,000

$1,113,361,000

$1,030,921,000

'

'

'

'

'

'

'

'

'

'

'

$300,000,000

'

$299,063,000

$298,893,000

$298,837,000

'

$400,000,000

'

'

'

'

'

'

'

'

Interest rate on notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.25%

'

'

'

6.60%

'

'

'

4.25%

'

'

'

'

'

'

'

'

Maturity date, year

'

'

'

'

'

'

'

'

'

'

'

'

'

'2020

'

'2017

'

'

'2018

'

'

'2024

'

'

'

'

'

'

'

'

'

Basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.10%

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding borrowing under credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

70,000,000

'

482,371,000

'

234,101,000

314,998,000

'

Credit facility commitment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

350,000,000

'

250,000,000

'

150,000,000

'

'

250,000,000

Extended maturity date, trade receivable facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30-Sep-16

'

'

'

'

Senior unsecured revolving facility, maturity period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

Debt covenant

'

'

'

'

'

'3.50x

'3.75x

'

'

'

'3.75x

'

'3.50x

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reduction of consolidated debt in the debt ratio calculation

'

'

'

'

'

'

'

50,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum consolidated debt reduction for unrestricted cash and cash equivalents for debt covenant calculation

'

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amendment consolidated EBITDA

'

'

'

'

'

'

'

'

'

'

'

95,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisition integration expenses

'

'

'

'

'

'

'

'

88,959,000

88,959,000

'

70,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding letters of credit

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,507,000

'

'

'

'

'

'

'

Additional interest expense

300,000

279,000

883,000

823,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Increase in annual interest expense due to ongoing amortization of the terminated value of the swap agreements

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,200,000

'

'

'

'

'

'

'

'

'

'

'

'

Financial_Instruments_Addition

Financial Instruments - Additional Information (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014
				Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions	'	'	'	'
Maturities of cash equivalents, in months	'	'	'	'Three
Long-term debt, carrying values	$1,618,275,000	$1,030,921,000	$1,113,361,000	'
Long-term debt, fair values	$1,707,920,000	$1,068,324,000	$1,152,906,000	'

Schedule_of_Estimated_Effectiv

Schedule of Estimated Effective Income Tax Rate (Detail)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Income Taxes	'	'
Continuing operations	39.70%	25.90%
Discontinued operations	27.60%	35.60%
Consolidated overall	39.70%	25.80%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	0 Months Ended	9 Months Ended
	Dec. 31, 2013	Sep. 30, 2014
Income Tax Contingency	'	'
Increase noncurrent deferred tax liabilities	$1,334,000	'
Reduction of deferred tax asset for net operating losses	'	5,300,000
Uncertain tax positions assumed in connection with an acquisition	'	5,963,000
Estimated unrecognized tax benefits, decrease as a result of tax position taken in prior years	'	-8,530,000
Unrecognized tax benefits that would impact effective tax rate	'	$9,083,000
Earliest Tax Year	'	'
Income Tax Contingency	'	'
Open tax years	'	'2009
Earliest Tax Year | Foreign Tax Authority	'	'
Income Tax Contingency	'	'
Expiration date of statute of limitations	'	'2010
Earliest Tax Year | Domestic Tax Authority	'	'
Income Tax Contingency	'	'
Expiration date of statute of limitations	'	'2010
Latest Tax Year	'	'
Income Tax Contingency	'	'
Open tax years	'	'2013
Latest Tax Year | Foreign Tax Authority	'	'
Income Tax Contingency	'	'
Expiration date of statute of limitations	'	'2011
Latest Tax Year | Domestic Tax Authority	'	'
Income Tax Contingency	'	'
Expiration date of statute of limitations	'	'2011

Unrecognized_Tax_Benefits_Excl

Unrecognized Tax Benefits Excluding Interest Correlative Effects and Indirect Benefits (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Reconciliation of Unrecognized Tax Benefits	'
Unrecognized tax benefits at beginning of period	$11,826
Gross increases - tax positions in prior years	1,898
Gross decreases - tax positions in prior years	-204
Gross increases - tax positions in current year	1,418
Gross increases as a result of lapse of statute of limitations	4,442
Gross decreases as a result of lapse of statute of limitations	-6,314
Increases - uncertain tax positions assumed in connection with an acquisition	5,963
Unrecognized tax benefits at end of period	$19,029

Pension_and_Postretirement_Ben2

Pension and Postretirement Benefits - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Pension and Other Postretirement Benefits Disclosure [Line Items]	'
Estimated contributions to the pension plans in calendar-year 2014	$25,500,000
Estimated contributions to the pension plans in the quarter ending December 31, 2014	$1,380,000

Schedule_of_Components_of_Net_

Schedule of Components of Net Periodic Benefit Cost (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Pension	'	'	'	'
Pension and Other Postretirement Benefits Disclosure [Line Items]	'	'	'	'
Service cost	$4,996	$4,030	$12,129	$12,091
Interest cost	7,979	5,756	20,952	17,268
Expected return on assets	-8,627	-6,668	-24,030	-20,003
Prior service cost (credit)	111	112	334	337
Actuarial loss (gain)	1,011	3,920	3,034	11,760
Settlement charge	'	729	'	729
Termination benefit cost	13,680	'	13,680	'
Net periodic benefit cost (credit)	19,150	7,879	26,099	22,182
Postretirement Benefit	'	'	'	'
Pension and Other Postretirement Benefits Disclosure [Line Items]	'	'	'	'
Service cost	57	57	150	170
Interest cost	302	253	861	760
Prior service cost (credit)	-814	-814	-2,441	-2,441
Actuarial loss (gain)	-66	6	-199	19
Net periodic benefit cost (credit)	($521)	($498)	($1,629)	($1,492)

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Commitments and Contingencies [Line Items]	'	'	'
Due from affiliate	$6,000,000	'	$6,000,000
Revolving Line Of Credit Expires In July 2013	'	'	'
Commitments and Contingencies [Line Items]	'	'	'
Guarantee of affiliate's obligations	24,000,000	'	'
Loan Due May 2016	'	'	'
Commitments and Contingencies [Line Items]	'	'	'
Loan to affiliate	'	3,402,000	'
Loan to affiliate, due date	'2016-05	'	'
Due from affiliate	$1,605,000	'	$2,984,000

Business_Segments_Additional_I

Business Segments - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
			Segment
Segment Reporting Information [Line Items]	'	'	'	'
Reportable business segments	'	'	3	'
Total revenues	$1,003,723	$665,320	$2,101,578	$1,610,555
Intersegment Eliminations	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	$22,061	'	$22,061	'

Financial_Data_for_Continuing_

Financial Data for Continuing Operations for Corporations Reportable Business Segments (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	$1,003,723	$665,320	$2,101,578	$1,610,555
Net Sales	917,942	600,457	1,899,557	1,451,848
Earnings (Loss) from operations, Total	115,956	108,843	196,300	155,157
Total Aggregates Business	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	823,636	604,704	1,792,457	1,428,366
Net Sales	749,749	544,663	1,612,095	1,284,253
Earnings (Loss) from operations, Total	163,629	97,335	234,688	125,795
Cement	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	115,743	'	115,743	'
Net Sales	109,521	'	109,521	'
Earnings (Loss) from operations, Total	18,278	'	18,278	'
Specialty Products	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	64,344	60,616	193,378	182,189
Net Sales	58,672	55,794	177,941	167,595
Earnings (Loss) from operations, Total	17,697	17,267	54,976	53,071
Mid-America Group	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	271,096	255,737	627,331	592,794
Net Sales	244,309	231,807	569,545	540,209
Earnings (Loss) from operations, Total	71,185	67,162	116,703	100,915
Southeast Group	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	73,217	69,490	208,205	185,676
Net Sales	68,042	64,871	194,148	171,456
Earnings (Loss) from operations, Total	329	-1,386	-7,084	-14,949
West Group	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total revenues	479,323	279,477	956,921	649,896
Net Sales	437,398	247,985	848,402	572,588
Earnings (Loss) from operations, Total	92,115	31,559	125,069	39,829
Corporate	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Earnings (Loss) from operations, Total	($83,648)	($5,759)	($111,642)	($23,709)

Asset_Employed_for_Continuing_

Asset Employed for Continuing Operations for Corporations Reportable Business Segments (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	$7,338,858	$3,259,826	$3,337,105
Total Aggregates Business	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	3,815,359	2,884,899	2,961,016
Cement	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	3,038,802	'	'
Specialty Products	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	150,068	154,024	153,334
Mid-America Group	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	1,313,472	1,242,394	1,270,025
Southeast Group	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	604,261	611,906	628,805
West Group	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	1,897,626	1,030,599	1,062,186
Corporate	'	'	'
Segment Reporting, Asset Reconciling Item [Line Items]	'	'	'
Assets employed, Total	$334,629	$220,903	$222,755

Net_Sales_By_Product_Line_Deta

Net Sales By Product Line (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	$917,942	$600,457	$1,899,557	$1,451,848
Gross profit (loss)	195,593	143,108	357,030	262,925
Aggregates	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	478,834	411,206	1,164,692	1,016,238
Gross profit (loss)	119,277	108,166	229,471	189,171
Asphalt	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	26,873	23,787	59,998	52,231
Gross profit (loss)	7,356	7,322	10,799	9,770
Ready Mixed Concrete	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	183,715	41,765	274,103	103,347
Gross profit (loss)	18,628	3,124	28,554	4,911
Road Paving	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	60,327	67,905	113,302	112,437
Gross profit (loss)	6,897	4,286	2,665	-285
Total Aggregates Business	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	749,749	544,663	1,612,095	1,284,253
Gross profit (loss)	152,158	122,898	271,489	203,567
Cement	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	109,521	'	109,521	'
Gross profit (loss)	24,194	'	24,194	'
Specialty Products	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Net Sales	58,672	55,794	177,941	167,595
Gross profit (loss)	20,043	19,919	62,192	60,784
Corporate	'	'	'	'
Business Combination, Separately Recognized Transactions	'	'	'	'
Gross profit (loss)	($802)	$291	($845)	($1,426)

Components_of_Change_in_Other_

Components of Change in Other Assets and Liabilities Net (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Schedule of Cash Flow, Supplemental	'	'
Other current and noncurrent assets	$3,998	($42)
Accrued salaries, benefits and payroll taxes	27,911	-1,307
Accrued insurance and other taxes	10,510	5,761
Accrued income taxes	7,096	18,369
Accrued pension, postretirement and postemployment benefits	-2,136	-10,431
Other current and noncurrent liabilities	-742	13,228
Change in other assets and liabilities	$46,637	$25,578

Noncash_Investing_and_Financin

Noncash Investing and Financing Activities (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Schedule of Cash Flow, Supplemental	'
Acquisition of assets through capital lease	$7,788
Acquisition of land through seller financing	1,500
Acquisition of land through asset swap	2,091
Acquisition of TXI assets and liabilities assumed through issuances of common stock and options (See Note 2)	$2,691,986