Eagle Materials (EXP) 10-K 23 May 14 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Mar. 31, 2014	20-May-14	Sep. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Mar-14	'	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'EXP	'	'
Entity Registrant Name	'EAGLE MATERIALS INC	'	'
Entity Central Index Key	'0000918646	'	'
Current Fiscal Year End Date	'--03-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	50,046,850	'
Entity Public Float	'	'	$3.50

Consolidated_Statements_of_Ear

Consolidated Statements of Earnings (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Statement [Abstract]	'	'	'
Revenues	$898,396	$642,562	$495,023
Cost of Goods Sold	712,937	539,317	454,546
Gross Profit	185,459	103,245	40,477
Equity in Earnings of Unconsolidated Joint Venture	37,811	32,507	28,528
Corporate General and Administrative Expense	-24,552	-23,918	-19,617
Other Operating Income (Loss)	1,368	-1,232	356
Acquisition, Litigation and Other Expense	'	-10,683	-9,117
Loss on Debt Retirement	'	'	-2,094
Interest Expense, net	-18,282	-15,823	-16,621
Earnings Before Income Taxes	181,804	84,096	21,912
Income Taxes	-57,561	-26,352	-3,180
Net Earnings	$124,243	$57,744	$18,732
EARNINGS PER SHARE	'	'	'
Basic	$2.53	$1.24	$0.42
Diluted	$2.49	$1.22	$0.42
AVERAGE SHARES OUTSTANDING	'	'	'
Basic	49,090,750	46,622,646	44,224,924
Diluted	49,939,165	47,340,450	44,515,981
CASH DIVIDENDS PER SHARE	$0.40	$0.40	$0.40

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Earnings (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Statement Of Income And Comprehensive Income [Abstract]	'	'	'
Net Earnings	$124,243	$57,744	$18,732
Net Actuarial Gains (Losses) of Defined Benefit Plans:	'	'	'
Unrealized gain during the period, net of tax expense of $1,173, $1,071 and $1,517	-2,399	-1,988	-2,818
Amortization of Net Actuarial Loss, net of tax benefit of $333, $249 and $105	840	462	195
Comprehensive Earnings	$122,684	$56,218	$16,109

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Earnings (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Statement Of Income And Comprehensive Income [Abstract]	'	'	'
Unrealized gain (loss) during the period, net of tax expense (benefit)	$1,173	$1,071	$1,517
Amortization of Net Actuarial Loss, net of tax benefit	$333	$249	$105

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Current Assets -	'	'
Cash and Cash Equivalents	$6,482	$3,897
Accounts and Notes Receivable, net	102,917	87,543
Inventories	187,096	156,380
Income Tax Receivable	'	2,443
Prepaid and Other Assets	10,465	11,008
Total Current Assets	306,960	261,271
Property, Plant and Equipment -	1,660,975	1,599,992
Less: Accumulated Depreciation	-676,924	-614,268
Property, Plant and Equipment, net	984,051	985,724
Notes Receivable	3,063	3,893
Investment in Joint Venture	43,008	42,946
Goodwill and Intangible Assets, net	160,690	162,400
Other Assets	13,757	19,999
Total Assets	1,511,529	1,476,233
Current Liabilities -	'	'
Accounts Payable	57,098	58,880
Accrued Liabilities	41,520	41,349
Income Tax Payable	702	'
Current Portion of Long-term Debt	9,500	'
Total Current Liabilities	108,820	100,229
Long-term Debt	371,759	489,259
Other Long-term Liabilities	53,678	51,547
Deferred Income Taxes	145,773	139,028
Total Liabilities	680,030	780,063
Stockholders' Equity -	'	'
Preferred Stock, Par Value $0.01; Authorized 5,000,000 Shares; None Issued	'	'
Common Stock, Par Value $0.01; Authorized 100,000,000 Shares; Issued and Outstanding 50,053,738 and 49,503,496 Shares, respectively.	501	495
Capital in Excess of Par Value	253,524	224,053
Accumulated Other Comprehensive Losses	-5,483	-7,042
Retained Earnings	582,957	478,664
Total Stockholders' Equity	831,499	696,170
Liabilities and Stockholders' Equity, Total	$1,511,529	$1,476,233

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Mar. 31, 2013
Statement Of Financial Position [Abstract]	'	'
Preferred Stock, Par Value	$0.01	$0.01
Preferred Stock, Authorized	5,000,000	5,000,000
Preferred Stock, Issued	'	'
Common Stock, Par Value	$0.01	$0.01
Common Stock, Authorized	100,000,000	100,000,000
Common Stock, Issued	50,053,738	49,503,496
Common Stock, Outstanding	50,053,738	49,503,496

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES	'	'	'
Net Earnings	$124,243	$57,744	$18,732
Adjustments to Reconcile Net Earnings to Net Cash Provided by Operating Activities, Net of Effect of Non-Cash Activity -	'	'	'
Depreciation, Depletion and Amortization	70,021	56,850	50,124
Deferred Income Tax Provision	5,746	6,155	2,188
Stock Compensation Expense	10,136	9,002	5,509
Excess Tax Benefits from Share Based Payment Arrangements	-8,067	-6,493	-1,568
Equity in Earnings of Unconsolidated Joint Venture	-37,811	-32,507	-28,528
Distributions from Joint Venture	37,750	28,500	23,250
Changes in Operating Assets and Liabilities:	'	'	'
Accounts and Notes Receivable	-12,876	-7,771	-10,452
Inventories	-32,714	-14,186	-8,369
Accounts Payable and Accrued Liabilities	6,504	24,610	3,327
Other Assets	-3,511	-2,679	-2,423
Income Taxes Payable	11,212	5,182	9,062
Net Cash Provided by Operating Activities	170,633	124,407	60,852
Additions to Property, Plant and Equipment	-59,490	-53,011	-26,099
Acquisition	'	-453,420	'
Net Cash Used in Investing Activities	-59,490	-506,431	-26,099
CASH FLOWS FROM FINANCING ACTIVITIES	'	'	'
Increase (Decrease) in Credit Facility	-108,000	227,000	68,000
Repayment of Senior Notes	'	-4,677	-88,064
Dividends Paid to Stockholders	-19,899	-18,533	-17,876
Net Proceeds from Offering of Common Stock	'	154,832	'
Proceeds from Stock Option Exercises	14,187	19,645	7,138
Shares Redeemed to Settle Employee Taxes on Stock Compensation	-2,913	-3,569	-912
Payment of Debt Acquisition Costs	'	-1,751	'
Excess Tax Benefits from Share Based Payment Arrangements	8,067	6,493	1,568
Net Cash Provided by (Used in) Financing Activities	-108,558	379,440	-30,146
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	2,585	-2,584	4,607
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	3,897	6,481	1,874
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$6,482	$3,897	$6,481

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Losses [Member]
In Thousands
Beginning balance at Mar. 31, 2011	$461,514	$444	$24,859	$439,104	($2,893)
Net Earnings	18,732	'	'	18,732	'
Stock Option Exercises and Restricted Share Vesting	7,138	9	7,129	'	'
Tax Benefit-Stock Option Exercise	1,107	'	1,107	'	'
Dividends to Stockholders	-17,954	'	'	-17,954	'
Stock Compensation Expense	5,509	'	5,509	'	'
Shares Redeemed to Settle Employee Taxes	-912	'	-912	'	'
Unfunded Pension Liability, net of tax	-2,623	'	'	'	-2,623
Ending Balance at Mar. 31, 2012	472,511	453	37,692	439,882	-5,516
Net Earnings	57,744	'	'	57,744	'
Net proceeds from Equity Offering	154,832	35	154,797	'	'
Stock Option Exercises and Restricted Share Vesting	19,645	8	19,637	'	'
Tax Benefit-Stock Option Exercise	6,493	'	6,493	'	'
Dividends to Stockholders	-18,962	'	'	-18,962	'
Stock Compensation Expense	9,002	'	9,002	'	'
Shares Redeemed to Settle Employee Taxes	-3,569	-1	-3,568	'	'
Unfunded Pension Liability, net of tax	-1,526	'	'	'	-1,526
Ending Balance at Mar. 31, 2013	696,170	495	224,053	478,664	-7,042
Net Earnings	124,243	'	'	124,243	'
Stock Option Exercises and Restricted Share Vesting	14,187	5	14,182	'	'
Tax Benefit-Stock Option Exercise	8,067	'	8,067	'	'
Dividends to Stockholders	-19,950	'	'	-19,950	'
Stock Compensation Expense	10,136	'	'	'	'
Stock Compensation Expense	10,136	1	10,135	'	'
Shares Redeemed to Settle Employee Taxes	-2,913	'	-2,913	'	'
Unfunded Pension Liability, net of tax	1,559	'	'	'	1,559
Ending Balance at Mar. 31, 2014	$831,499	$501	$253,524	$582,957	($5,483)

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Significant Accounting Policies	'
	(A) Significant Accounting Policies
	Basis of Presentation –
	The consolidated financial statements include the accounts of Eagle Materials Inc. and its majority-owned subsidiaries (“EXP” or the “Company”), which may be referred to as “our”, “we”, or “us”. All intercompany balances and transactions have been eliminated. EXP is a holding company whose assets consist of its investments in its subsidiaries, joint venture, intercompany balances and holdings of cash and cash equivalents. The businesses of the consolidated group are conducted through EXP’s subsidiaries. The Company conducts one of its cement plant operations through a joint venture, Texas Lehigh Cement Company L.P., which is located in Buda, Texas (the “Joint Venture”). Investments in the Joint Venture and affiliated companies owned 50% or less are accounted for using the equity method of accounting. The Equity in Earnings of Unconsolidated Joint Venture has been included for the same period as our March 31 year end.
	The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Cash and Cash Equivalents –
	Cash equivalents include short-term, highly liquid investments with original maturities of three months or less and are recorded at cost, which approximates market value.
	Accounts and Notes Receivable –
	Accounts and notes receivable have been shown net of the allowance for doubtful accounts of $5.8 million and $5.1 million at March 31, 2014 and 2013, respectively. We perform ongoing credit evaluations of our customers’ financial condition and generally require no collateral from our customers. The allowance for non-collection of receivables is based upon analysis of economic trends in the construction industry, detailed analysis of the expected collectability of accounts receivable that are past due and the expected collectability of overall receivables. We have no significant credit risk concentration among our diversified customer base.
	We had notes receivable totaling approximately $9.3 million at March 31, 2014, of which approximately $6.3 million has been classified as current and presented with accounts receivable on the balance sheet. We lend funds to certain companies in the ordinary course of business, and the notes bear interest, on average, at 4.3%, which will vary based on changes to LIBOR. Remaining unpaid amounts, plus accrued interest, mature on various dates between 2014 and 2017. The notes are collateralized by certain assets of the borrowers, namely property and equipment. We monitor the credit risk of each borrower by focusing on the timeliness of payments, review of credit history and credit metrics and interaction with the borrowers. At March 31, 2014 and 2013, approximately $0.3 million of our allowance for doubtful accounts is related to our notes receivable.
	Inventories –
	Inventories are stated at the lower of average cost (including applicable material, labor, depreciation, and plant overhead) or market. Inventories consist of the following:
		March 31,
		2014			2013
		(dollars in thousands)
	Raw Materials and Materials-in-Progress	$	82,319		$	60,026
	Finished Cement		19,173			18,077
	Gypsum Wallboard		7,144			6,855
	Aggregates		12,090			12,830
	Paperboard		4,102			2,867
	Repair Parts and Supplies		56,119			49,361
	Fuel and Coal		6,149			6,364
		$	187,096		$	156,380
	Property, Plant and Equipment –
	Property, plant and equipment are stated at cost. Major renewals and improvements are capitalized and depreciated. Annual maintenance is expensed as incurred. Depreciation is provided on a straight-line basis over the estimated useful lives of depreciable assets and totaled $67.3 million, $55.1 million and $48.9 million for the years ended March 31, 2014, 2013 and 2012, respectively. Raw material deposits are depleted as such deposits are extracted for production utilizing the units-of-production method. Costs and accumulated depreciation applicable to assets retired or sold are eliminated from the accounts and any resulting gains or losses are recognized at such time. The estimated lives of the related assets are as follows:
	Plants		20 to 30 years
	Buildings		20 to 40 years
	Machinery and Equipment		3 to 25 years
	We periodically evaluate whether current events or circumstances indicate that the carrying value of our depreciable assets may not be recoverable. At March 31, 2014 and 2013, management believes no events or circumstances indicate that the carrying value may not be recoverable.
	We temporarily idled our gypsum manufacturing facility in Bernalillo, N.M. beginning in December 2009, due to cyclical low gypsum wallboard demand. The carrying value of the Bernalillo plant and equipment at March 31, 2014 was $2.9 million and $1.6 million, respectively and we continue to depreciate the assets over their estimated useful life. We currently have a strong market position in New Mexico, and our Albuquerque gypsum wallboard facility is operating at close to capacity. We plan on resuming manufacturing at the Bernalillo facility in the future when additional capacity is needed to meet demand for our products. Costs of maintaining the facility during the idling are not significant, and the facility was generating positive cash flow prior to being idled; therefore, we have determined that the value of the plant and equipment is not impaired. We are not currently considering the permanent closure of the Bernalillo facility. Any decision to permanently close Bernalillo would be the result of future changes in the building materials industry in the southwest United States and Rocky Mountain region, including changes in the production capacity or operations of our competitors, demand for gypsum wallboard or general macro-economic conditions, which we do not foresee at the present time. If we were to permanently close the Bernalillo facility, or if our expectations as to its use changed such that we project the future undiscounted cash flows from its operations would be insufficient to recover its carrying value due to the factors described above, or for any other reason, we would recognize impairment at that time.
	Impairment or Disposal of Long-Lived and Intangible Assets –
	We evaluate the recoverability of our long-lived assets and certain identifiable intangibles, such as permits and customer contracts, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets, such as plants, buildings and machinery and equipment, including mining assets, is measured by comparing the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. Such evaluations for impairment are significantly impacted by estimates of future prices for our products, capital needs, economic trends in the construction sector and other factors. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds their fair value. Assets to be disposed of by sale are reflected at the lower of their carrying amount or fair value less cost to sell.
	Goodwill and Intangible Assets –
	Goodwill. Goodwill is subject to at least an annual assessment for impairment by applying a fair-value-based test. We have elected to test for goodwill impairment in the fourth quarter of each fiscal year. The goodwill impairment test is a two-step process, which requires us to make judgments in determining what assumptions to use in the calculation. The first step of the process consists of estimating the fair value of each reporting unit based on a discounted cash flow model using revenues and profit forecasts and comparing those estimated fair values with the carrying value; a second step is performed, if necessary, to compute the amount of the impairment by determining an “implied fair value” of goodwill. Similar to the review for impairment of other long-lived assets, evaluations for impairment are significantly impacted by estimates of future prices for our products, capital needs, economic trends and other factors.
	Intangible Assets: Intangible assets at March 31, 2014 and 2013 consist of the following:
		March 31, 2014
		Amortization			Cost			Accumulated			Net
		Period						Amortization
		(dollars in thousands)
	Intangible Assets Subject to Amortization:
	Customer contracts and relationships		15 years		$	6,060		$	(1,580	)	$	4,480
	Sales contracts		4 years			2,500			(833	)		1,667
	Permits		40 years			27,240			(5,212	)		22,028
	Goodwill					132,515			—			132,515
	Total intangible assets and goodwill				$	168,315		$	(7,625	)	$	160,690
		31-Mar-13
		Amortization			Cost			Accumulated			Net
		Period						Amortization
		(dollars in thousands)
	Intangible Assets Subject to Amortization:
	Customer contracts and relationships		15 years		$	6,060		$	(1,176	)	$	4,884
	Sales contracts		4 years			2,500			(208	)		2,292
	Permits		40 years			27,240			(4,531	)		22,709
	Goodwill					132,515			—			132,515
	Total intangible assets and goodwill				$	168,315		$	(5,915	)	$	162,400
	Amortization expense of intangibles was $1.7 million, $1.0 million and $0.6 million for the years ended March 31, 2014, 2013 and 2012, respectively. Amortization expense is expected to be approximately $1.7 million per year for fiscal years 2015 and 2016, $1.5 million in fiscal 2017, and $1.0 million for fiscal years 2018 and 2019.
	Other Assets –
	Other assets are primarily composed of loan fees and financing costs, deferred expenses, and deposits.
	Income Taxes –
	Income taxes are accounted for using the asset and liability method. Deferred taxes are recognized for the tax consequences of temporary differences by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities. The effect on deferred taxes of a change in tax rates is recognized in earnings in the period that includes the enactment date. In addition, we recognize future tax benefits to the extent that such benefits are more likely than not to be realized.
	Stock Repurchases –
	Our Board of Directors has approved the repurchase of a cumulative total of 31,610,605 shares, of which approximately 717,300 shares remain available for repurchase at March 31, 2014. We did not repurchase any shares in the open market during the years ended March 31, 2014, 2013 and 2012.
	Revenue Recognition –
	Revenue from the sale of cement, gypsum wallboard, paperboard, concrete and aggregates is recognized when title and ownership are transferred upon shipment to the customer. Fees for shipping and handling are recorded as revenue, while costs incurred for shipping and handling are recorded as expenses.
We classify amounts billed to customers for freight as revenues and freight costs as cost of goods sold, respectively, in the Consolidated Statements of Earnings. Approximately $113.1 million, $83.2 million and $66.0 million were classified as cost of goods sold in the years ended March 31, 2014, 2013 and 2012, respectively.
Other income (loss) includes lease and rental income, asset sale income, non-inventoried aggregates sales income, distribution center income and trucking income as well as other miscellaneous revenue items and costs which have not been allocated to a business segment.
Comprehensive Income/Losses –
As of March 31, 2014, we have an accumulated other comprehensive loss of $5.5 million, which is net of income taxes of $3.0 million, in connection with recognizing the difference between the fair value of the pension assets and the projected benefit obligation.
Consolidated Cash Flows – Supplemental Disclosures –
Interest payments made during the years ended March 31, 2014, 2013 and 2012 were $17.0 million, $14.6 million and $18.8 million, respectively.
We made net payments of $41.7 million and $14.8 million for federal and state income taxes in the years ended March 31, 2014 and 2013, respectively, and received a net refund of $8.0 million in the year ended March 31, 2012.
Statements of Consolidated Earnings – Supplemental Disclosures –
Maintenance and repair expenses are included in each segment’s costs and expenses. We incurred $ 77.4 million, $61.3 million and $37.6 million in the years ended March 31, 2014, 2013 and 2012, respectively, which is included in Cost of Goods Sold on the Consolidated Statement of Earnings.
Selling, general and administrative expenses of the operating units are included in Cost of Goods Sold on the Consolidated Statements of Earnings. Corporate general and administrative (“G&A”) expenses include administration, financial, legal, employee benefits and other corporate activities and are shown separately in the consolidated statements of earnings. Corporate G&A also includes stock compensation expense. See Note (J), Stock Option Plans, for more information.
Total selling, general and administrative expenses for each of the periods are summarized as follows:
	For the Years Ended March 31,
	2014			2013			2012
	(dollars in thousands)
Operating Units Selling, G&A	$	50,175		$	39,133		$	27,695
Corporate G&A		24,552			23,918			19,617
	$	74,727		$	63,051		$	47,312
During fiscal 2012, we repurchased $88.1 million of our senior debt at a premium, which was recorded inclusive of transaction costs. The amount of the premium plus transaction costs was $2.1 million.
Earnings Per Share –
	For the Years Ended March 31,
	2014			2013			2012
Weighted-Average Shares of Common Stock Outstanding		49,090,750			46,622,646			44,224,924
Effect of Dilutive Shares:
Assumed Exercise of Outstanding Dilutive Options		1,574,491			1,984,563			800,748
Less Shares Repurchased from Proceeds of Assumed Exercised Options		(1,032,359	)		(1,568,604	)		(652,046	)
Restricted Stock Units		306,283			301,845			142,355
Weighted-Average Common Stock and Dilutive Securities Outstanding		49,939,165			47,340,450			44,515,981
The “Less Shares Repurchased from Proceeds of Assumed Exercised Options” line includes unearned compensation related to outstanding stock options.
There were 146,696, 1,082,380 and 2,773,279 stock options at an average exercise price of $65.12 per share, $39.65 per share and $42.17 per share that were excluded from the computation of diluted earnings per share for the years ended March 31, 2014, 2013 and 2012, respectively, because such inclusion would have been anti-dilutive.
Fair Value Measures
Certain assets and liabilities are required to be recorded or disclosed at fair value. The estimated fair values of those assets and liabilities have been determined using market information and valuation methodologies. Changes in assumptions or estimation methods could affect the fair value estimates; however, we do not believe any such changes would have a material impact on our financial condition, results of operations or cash flows. There are three levels of inputs that may be used to measure fair value:
Level 1 – Quoted prices for identical assets and liabilities in active markets;
Level 2 – Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data; and
Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs.
New Accounting Standards –
There are no recent accounting pronouncements that materially impacted our financial statements during the current year, and we do not expect any accounting pronouncements to impact our financial statements in the next fiscal year.
Acquisition, Litigation and Other Expense
Acquisition and litigation expense consists primarily of expenses incurred during our acquisition, as discussed in Note (B), Acquisition, and significant legal expenses incurred during litigation, primarily litigation involving an ongoing lawsuit against the Internal Revenue Service (“IRS”), and an adverse arbitration ruling in fiscal 2012. See Note (I), Commitments and Contingencies, for more information about the outstanding lawsuit with the IRS and the results of the arbitration ruling.

Acquisition

Acquisition	12 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Acquisition	'
	(B) Acquisition
	On November 30, 2012, the Company completed the acquisition (the “Acquisition”) of certain assets of Lafarge North America Inc. (“Lafarge North America” or “the Sellers”). The Acquisition expanded the scope of our cement business in a geographic area that is complementary to, but does not overlap with, our existing cement business. The Acquisition also further positions the Company near energy growth markets where there is growing demand for our specialty oil well cement and other related products.
	The assets acquired by us in the Acquisition were used by the Sellers in connection with the business (the “Acquired Assets”) of producing, marketing and selling portland cement and concrete in Kansas, Missouri and Oklahoma, and include the following:
		•		two cement plants located in Sugar Creek, Missouri and Tulsa, Oklahoma;
		•		the related cement distribution terminals located in Sugar Creek and Springfield, Missouri; Omaha, Nebraska; Iola and Wichita, Kansas; and Oklahoma City, Oklahoma;
		•		two aggregates quarries near Sugar Creek, Missouri;
		•		eight ready-mix plants located in or near Kansas City, Missouri;
		•		certain fly ash operations conducted in the Kansas City, Missouri area; and
		•		certain related assets such as equipment, accounts receivable and inventory.
	In most cases, we acquired ownership of these assets from the Sellers. However, the cement plant located in Sugar Creek, Missouri was leased by the Sellers pursuant to a long-term lease containing a purchase option exercisable by payment of a nominal fee. This lease, including the purchase option, was transferred to us at the closing of the Acquisition. In addition, we assumed certain liabilities in the Acquisition, including accounts payable, contractual obligations, reclamation obligations and other liabilities related to the Acquired Assets.
	Purchase Price: The final purchase price (the “Purchase Price”) of the Acquisition was $450.7 million, which reflects a $2.7 million reduction from the preliminary purchase price to reflect actual working capital acquired at the closing. The reduction in purchase price was primarily related to adjustments to the final value of inventory and prepaid assets acquired. We funded the payment of the Purchase Price at closing and expenses incurred in connection with the Acquisition through a combination of borrowings under our bank credit facility and the proceeds from our issuance of common stock, which was completed on October 3, 2012.
	Recording of assets acquired and liabilities assumed: The transaction has been accounted for using the acquisition method of accounting which requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date. We engaged a third-party to perform a valuation to support our estimate of the fair value of certain assets acquired in the Acquisition. The estimated working capital amounts paid at the closing were adjusted by approximately $2.7 million to reflect actual working capital acquired.
	The preparation of the valuation of the assets acquired and liabilities assumed in the Acquisition requires the use of significant assumptions and estimates. Critical estimates include, but are not limited to, future expected cash flows, including projected revenues and expenses, and applicable discount rates. These estimates are based on assumptions that we believe to be reasonable. However, actual results may differ from these estimates.
	Under the acquisition method of accounting, the total purchase price was allocated to the net tangible and intangible assets and assumed liabilities based on their estimated fair values at the acquisition date. Based on the fair value of tangible and intangible assets acquired and liabilities assumed the purchase price is allocated as follows:
	Purchase Price Allocation (in thousands)
	Cash and cash equivalents		$	—
	Accounts Receivable			23,432
	Inventories			20,361
	Prepaid and Other Assets			3,511
	Property and Equipment			407,260
	Intangible Assets			12,500
	Accounts Payable			(9,070	)
	Accrued Liabilities			(3,501	)
	Other Long-term Liabilities			(1,060	)
	Total Net Assets			453,433
	Goodwill			—
	Initial Purchase Price		$	453,433
	Final Working Capital Adjustment			(2,734	)
	Final Purchase Price		$	450,699
	Intangible Assets: The following table is a summary of the fair value estimates of the identifiable intangible assets (in thousands) and their weighted-average useful lives:
			Weighted			Fair Value
			Average Life
	Customer Relationships			15		$	4,760
	Sales Contracts			4			2,500
	Permits			40			5,240
	Total Intangible Assets					$	12,500
	Actual and pro forma impact of the Acquisition: The following table presents the net sales and operating income of the Acquired Assets that has been included in our consolidated statement of earnings from November 30, 2012 through March 31, 2013, and for the fiscal year ended March 31, 2014:
			For the Fiscal Year Ended
			March 31,
			2014			2013
			(dollars in thousands)
	Net Sales		$	158,764		$	28,892
	Operating income (loss)		$	25,249		$	(12,531	)
	The unaudited pro forma results presented below include the effects of the Acquisition as if it had been consummated as of April 1, 2011. The pro forma results include the amortization associated with an estimate for acquired intangible assets and interest expense associated with debt used to fund the Acquisition, depreciation from the fair value adjustments for property and equipment, and the impact on earnings per share of the issuance of common stock in connection with the Acquisition. To better reflect the combined operating results, material nonrecurring charges directly related to the Acquisition of $6.1 million have been excluded from pro forma net income for the twelve month periods ended March 31, 2013 and 2012.
			For the Fiscal Year Ended
			March 31,
			2013			2012
			(dollars in thousands)
	Revenues		$	792,979		$	660,401
	Net Income		$	71,361		$	7,460
	Earnings per share – basis		$	1.48		$	0.16
	Earnings per share – diluted		$	1.45		$	0.16
	Weighted Average Shares Outstanding:
	Basic			48,352,346			47,647,924
	Diluted			49,070,150			47,965,981
	The pro forma results do not include any anticipated synergies or other expected benefits of the Acquisition. Accordingly, the unaudited pro forma results are not necessarily indicative of either future results of operations or results that might have been achieved had the Acquisition been consummated as of April 1, 2011.

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
	Mar. 31, 2014
Property Plant And Equipment [Abstract]	'
Property, Plant and Equipment	'
	(C) Property, Plant and Equipment
	Cost by major category and accumulated depreciation are summarized as follows:
		March 31,
		2014			2013
		(dollars in thousands)
	Land and Quarries	$	171,987		$	154,710
	Plants		1,357,594			1,324,489
	Buildings, Machinery and Equipment		111,263			110,138
	Construction in Progress		20,131			10,655
			1,660,975			1,599,992
	Accumulated Depreciation		(676,924	)		(614,268	)
		$	984,051		$	985,724
	Included in Property, Plant and Equipment are $124.9 million and $83.9 million of mining and related assets (net of accumulated depreciation) at March 31, 2014 and 2013, respectively.

Accrued_Expenses

Accrued Expenses	12 Months Ended
	Mar. 31, 2014
Payables And Accruals [Abstract]	'
Accrued Expenses	'
	(D) Accrued Expenses
	Accrued expenses at March 31, 2014 and 2013 consist of the following:
		March 31,
		2014		2013
		(dollars in thousands)
	Payroll and Incentive Compensation	$	12,855	$	11,827
	Benefits		10,158		10,349
	Interest		4,813		4,813
	Property Taxes		2,801		3,235
	Power and Fuel		2,132		3,146
	Legal		1,831		792
	Sales and Use Tax		658		591
	Acquisition Related Expenses		—		2,023
	Other		6,272		4,573
		$	41,520	$	41,349

Indebtedness

Indebtedness	12 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Indebtedness	'
	(E) Indebtedness
	Long-term debt consists of the following:
		As of
		March 31,			March 31,
		2014			2013
		(dollars in thousands)
	Bank Credit Facility	$	189,000		$	297,000
	Senior Notes		192,259			192,259
	Total Debt		381,259			489,259
	Less: Current Portion of Long-term Debt		(9,500	)		—
	Long-term Debt	$	371,759		$	489,259
	On December 16, 2011, we accepted for repurchase $59.1 million in aggregate principal amount of our Series 2007A Senior Notes for $60.2 million, plus accrued interest of $0.3 million, and $29.0 million in aggregate principal amount of our Series 2005A Senor Notes for $29.6 million, plus accrued interest of $0.4 million. The purchase of the Senior Notes was funded through borrowings under our Bank Credit Facility. The premium paid on these repurchases has been included in Loss on Debt Retirement in our Consolidated Statement of Earnings for the fiscal year ended March 31, 2012.
	The weighted-average interest rate of Senior Notes during fiscal 2014, 2013 and 2012 was 5.81%, 5.81% and 5.78%, respectively. The average interest rate of the Senior Notes was 5.81% at both March 31, 2014 and 2013.
	The weighted-average interest rate of bank debt borrowings during fiscal 2014, 2013 and 2012 was 1.9%, 2.0% and 2.6%, respectively. The interest rate on the bank debt was 1.5% and 2.0% at March 31, 2014 and 2013, respectively.
	Our maturities of long-term debt during the next five fiscal years and thereafter are as follows:
	Fiscal Year	Amount
	2015	$	9,500
	2016		246,045
	2017		8,000
	2018		81,214
	2019		—
	Thereafter		36,500
	Total	$	381,259
	Senior Notes -
	We entered into a Note Purchase Agreement on November 15, 2005 (the “2005 Note Purchase Agreement”) related to our sale of $200 million of senior, unsecured notes, designated as Series 2005A Senior Notes (the “Series 2005A Senior Notes”) in a private placement transaction. The Series 2005A Senior Notes, which are guaranteed by substantially all of our subsidiaries, were sold at par and issued in three tranches on November 15, 2005. Since entering into the 2005 Note Purchase Agreement, we have repurchased $81.1 million in principal of the Series 2005A Senior Notes (in periods prior to the fiscal year ended March 31, 2013). During November 2012, Tranche A of the Series 2005A Senior Notes matured and we retired the remaining $4.7 million in notes from this Tranche. Following these repurchases and maturities, the amounts outstanding for each of the remaining tranches are as follows:
		Principal			Maturity Date		Interest Rate
	Tranche B	$	57.0 million			November 15, 2015		5.38	%
	Tranche C	$	57.2 million			15-Nov-17		5.48	%
	Interest for each tranche of Notes is payable semi-annually on May 15 and November 15 of each year until all principal is paid for the respective tranche.
	We also entered into an additional Note Purchase Agreement on October 2, 2007 (the “2007 Note Purchase Agreement”) related to our sale of $200 million of senior, unsecured notes, designated as Series 2007A Senior Notes (the “Series 2007A Senior Notes”) in a private placement transaction. The Series 2007A Senior Notes, which are guaranteed by substantially all of our subsidiaries, were sold at par and issued in four tranches on October 2, 2007. Since entering into the 2007 Note Purchase Agreement, we have repurchased $122.0 million in principal of the Series 2007A Senior Notes (in periods prior to the fiscal year ended March 31, 2013). Following the repurchase, the amounts outstanding for each of the four tranches are as follows:
		Principal			Maturity Date		Interest Rate
	Tranche A	$	9.5 million			October 2, 2014		6.08	%
	Tranche B	$	8.0 million			2-Oct-16		6.27	%
	Tranche C	$	24.0 million			2-Oct-17		6.36	%
	Tranche D	$	36.5 million			2-Oct-19		6.48	%
	Interest for each tranche of Notes is payable semi-annually on April 2 and October 2 of each year until all principal is paid for the respective tranche.
	We amended both the 2005 Note Purchase Agreement and 2007 Note Purchase Agreement (collectively, the “Note Purchase Agreements”) on September 26, 2012. The amendment to each Note Purchase Agreement, among other things, mirrors the amendments to the Credit Facility, by changing certain provisions in the negative covenants in order to allow for and facilitate the Acquisition, as well as to implement certain related changes to the financial covenants. These financial covenant changes primarily related to amending the definition of Consolidated EBITDA to allow the add-back to consolidated net income of certain transaction and other allocated overhead costs related to the Acquisition that are not expected to be incurred in the future as well as reasonably identifiable cost savings, improvements and synergies related to the purchase of the Acquired Assets.
	Our obligations under the 2005 Note Purchase Agreement and the 2007 Note Purchase Agreement (collectively referred to as the “Note Purchase Agreements”) and the Series 2005A Senior Notes and the Series 2007A Senior Notes (collectively referred to as “the Senior Notes”) are equal in right of payment with all other senior, unsecured debt of the Company, including our debt under the Credit Facility. The Note Purchase Agreements contain customary restrictive covenants, including covenants that place limits on our ability to encumber our assets, to incur additional debt, to sell assets, or to merge or consolidate with third parties, as well as certain cross covenants with the Credit Facility. We were in compliance with all financial ratios and tests at March 31, 2014 and throughout the fiscal year.
	Pursuant to a Subsidiary Guaranty Agreement, substantially all of our subsidiaries have guaranteed the punctual payment of all principal, interest, and Make-Whole Amounts (as defined in the Note Purchase Agreements) on the Senior Notes and the other payment and performance obligations of the Company contained in the Senior Notes and in the Note Purchase Agreements. We are permitted, at our option and without penalty, to prepay from time to time at least 10% of the original aggregate principal amount of the Senior Notes at 100% of the principal amount to be prepaid, together with interest accrued on such amount to be prepaid to the date of payment, plus a Make-Whole Amount. The Make-Whole Amount is computed by discounting the remaining scheduled payments of interest and principal of the Senior Notes being prepaid at a discount rate equal to the sum of 50 basis points and the yield to maturity of U.S. treasury securities having a maturity equal to the remaining average life of the Senior Notes being prepaid.
	Bank Debt -
	On December 16, 2010, we entered into a $300.0 million revolving Credit Facility, which was amended on September 26, 2012 and is scheduled to expire on December 16, 2015. The recent amendment to the Credit Facility increased available revolving borrowings from $300.0 million to $400.0 million (including an increase in the swingline loan sublimit from $15.0 million to $25.0 million) and changed certain provisions in the negative covenants in order to allow for or facilitate the Acquisition, as well as to implement certain related changes to the financial covenants. These financial covenant changes primarily related to amending the definition of Consolidated EBITDA to allow the add-back to consolidated net income of certain transaction and other allocated overhead costs related to the Acquisition that are not expected to be incurred in the future. Borrowings under the Credit Facility are guaranteed by substantially all of the Company’s subsidiaries. At the option of the Company, outstanding principal amounts on the Credit Facility bear interest at a variable rate equal to (i) LIBOR, plus an agreed margin (ranging from 100 to 225 basis points), which is to be established quarterly based upon the Company’s ratio of consolidated EBITDA, defined as earnings before interest, taxes, depreciation and amortization, to the Company’s consolidated indebtedness (the “Leverage Ratio”), or (ii) an alternative base rate which is the higher of (a) the prime rate or (b) the federal funds rate plus  1/2%, per annum plus an agreed margin (ranging from 0 to 125 basis points). Interest payments are payable, in the case of loans bearing interest at a rate based on the federal funds rate, quarterly, or in the case of loans bearing interest at a rate based on LIBOR, at the end of the LIBOR advance periods, which can be up to a period of six months at the option of the Company. The Company is also required to pay a commitment fee on unused available borrowings under the Credit Facility ranging from 10 to 35 basis points depending upon the Leverage Ratio. The Credit Facility contains customary covenants that restrict our ability to incur additional debt, encumber our assets, sell assets, make or enter into certain investments, loans or guaranties and enter into sale and leaseback arrangements. The Credit Facility also requires us to maintain a consolidated indebtedness ratio (calculated as consolidated indebtedness to consolidated earnings before interest, taxes, depreciation, amortization, certain transaction-related deductions and other non-cash deductions) of 3.5:1.0 or less and an interest coverage ratio (consolidated earnings before interest, taxes, depreciation, amortization, certain transaction-related deductions and other non-cash deductions to consolidated interest expense) of at least 2.5:1.0. The Credit Facility also limits our ability to make certain restricted payments, such as paying cash dividends; however, there are several exceptions to this restriction, including: (i) the Company may pay cash dividends in an aggregate amount of up to $50.0 million each fiscal year; and (ii) the Company may make restricted payments not otherwise permitted so long as, in each case, no default would result therefrom and our consolidated funded indebtedness ratio does not exceed 3.0:1.0. We had $189.0 million of borrowings outstanding under the Credit Facility at March 31 2014. Based on our Leverage Ratio, we had $203.6 million of available borrowings, net of the outstanding letters of credit, under the Credit Facility at March 31, 2014.
	The Credit Facility has a $50.0 million letter of credit facility. Under the letter of credit facility, the Company pays a fee at a per annum rate equal to the applicable margin for Eurodollar loans in effect from time to time plus a one-time letter of credit fee in an amount equal to 0.125% of the initial stated amount. At March 31, 2014, we had $7.4 million of letters of credit outstanding.
	As a result of the Acquisition, we succeeded to the leasehold interest held by Lafarge North America with respect to the cement plant located in Sugar Creek, Missouri, as well as its obligations under certain related industrial revenue bonds. In 1998, Lafarge North America had entered into a series of agreements, which were later amended in 2003, with the City of Sugar Creek, Missouri, in connection with the construction of improvements at the Sugar Creek cement plant. Under these agreements, Lafarge North America leased the Sugar Creek cement plant from the City of Sugar Creek, Missouri, which issued $150.0 million of tax-exempt and taxable industrial revenue bonds to partly finance the construction of such improvements. The lease payments due to the City of Sugar Creek under the Sugar Creek cement plant lease are equal in amount to the payments required to be made by the City of Sugar Creek to the holders of the industrial revenue bonds. Upon the closing of the Acquisition, funds for the retirement of $47.0 million of the industrial revenue bonds were placed into escrow by Lafarge North America, resulting in the defeasement of such bonds and leaving $103.0 million of industrial revenue bonds outstanding. The defeased bonds were subsequently paid in full in June 2013. The remaining $103.0 million of industrial revenue bonds held by Lafarge North America were transferred to a wholly owned subsidiary of the Company in connection with the Acquisition. Because we are now the holder of all of the outstanding industrial revenue bonds, no debt is reflected on our financial statements in connection with our lease of the Sugar Creek cement plant.
	On August 31, 2011, we entered into an Uncommitted Master Shelf Agreement (the “Shelf Agreement”) with John Hancock Life Insurance Company (U.S.A.) (“Hancock”). The Shelf Agreement provided the terms under which the Company could offer up to $75 million of its senior unsecured notes for purchase by Hancock or Hancock’s affiliates that become bound by the Shelf Agreement (collectively, “Purchasers”). The Shelf Agreement did not obligate the Company to sell, or the Purchasers to buy, any such notes, and had a term of two years. We did not sell any notes pursuant to the Shelf Agreement prior to its expiration on August 31, 2013.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	(F) Fair Value of Financial Instruments
	The fair value of our senior notes has been estimated based upon our current incremental borrowing rates for similar types of borrowing arrangements. The fair value of our Senior Notes at March 31, 2014 is as follows:
		Fair Value
		(dollars in
		thousands)
	Series 2005A Tranche B	$	59,526
	Series 2005A Tranche C		60,933
	Series 2007A Tranche A		9,676
	Series 2007A Tranche B		8,624
	Series 2007A Tranche C		26,208
	Series 2007A Tranche D		40,187
	The estimated fair value of our long-term debt was based on quoted prices of similar debt instruments with similar terms that are publicly traded (level 2 input). The carrying values of cash and cash equivalents, accounts and notes receivable, accounts payable and accrued liabilities approximate their fair values at March 31, 2014 due to the short-term maturities of these assets and liabilities. The fair value of our Credit Facility also approximates its carrying value at March 31, 2014.

Business_Segments

Business Segments	12 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Business Segments	'
	(G) Business Segments
	Operating segments are defined as components of an enterprise that engage in business activities that earn revenues, incur expenses and prepare separate financial information that is evaluated regularly by our chief operating decision maker in order to allocate resources and assess performance.
	We operate in four business segments: Cement, Gypsum Wallboard, Recycled Paperboard, and Concrete and Aggregates, with Gypsum Wallboard and Cement being our principal lines of business. These operations are conducted in the U.S. and include the mining of limestone and the manufacture, production, distribution and sale of portland cement (a basic construction material which is the essential binding ingredient in concrete), the mining of gypsum and the manufacture and sale of gypsum wallboard, the manufacture and sale of recycled paperboard to the gypsum wallboard industry and other paperboard converters, the sale of readymix concrete and the mining and sale of aggregates (crushed stone, sand, gravel and frac sand). These products are used primarily in commercial and residential construction, public construction projects and projects to build, expand and repair roads and highways and in oil and natural gas extraction.
	As further discussed below, we operate six cement plants, sixteen cement distribution terminals, five gypsum wallboard plants, including the plant temporarily idled in Bernalillo, N.M., a gypsum wallboard distribution center, a recycled paperboard mill, seventeen readymix concrete batch plant locations, four aggregates processing plant locations and a frac sand drying and screening plant. The principal markets for our cement products are Texas, northern Illinois (including Chicago), the central plains, the Rocky Mountains, northern Nevada, and northern California. Gypsum wallboard and recycled paperboard are distributed throughout the continental U.S, with the exception of the northeast. Concrete and aggregates are sold to local readymix producers and paving contractors in the Austin, Texas area, north of Sacramento, California and the greater Kansas City, Missouri area, while frac sand is currently sold in Texas.
	We conduct one of our six cement plant operations, Texas Lehigh Cement Company LP in Buda, Texas, through a Joint Venture. For segment reporting purposes only, we proportionately consolidate our 50% share of the Joint Venture’s revenues and operating earnings, which is consistent with the way management reports the segments within the Company for making operating decisions and assessing performance.
	We account for intersegment sales at market prices. The following table sets forth certain financial information relating to our operations by segment:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Revenues -
	Cement	$	438,224		$	304,125		$	243,978
	Gypsum Wallboard		387,016			306,529			217,633
	Paperboard		130,178			121,930			118,794
	Concrete and Aggregates		116,465			56,287			45,515
			1,071,883			788,871			625,920
	Less: Intersegment Revenues		(62,094	)		(49,987	)		(44,757	)
	Less: Joint Venture Revenues		(111,393	)		(96,322	)		(86,140	)
		$	898,396		$	642,562		$	495,023
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Intersegment Revenues -
	Cement	$	8,952		$	2,850		$	3,605
	Paperboard		52,119			46,393			40,485
	Concrete and Aggregates		1,023			744			667
		$	62,094		$	49,987		$	44,757
	Cement Sales Volumes (M tons) -
	Wholly-Owned		3,580			2,390			1,857
	Joint Venture		1,013			913			866
			4,593			3,303			2,723
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Operating Earnings -
	Cement	$	89,486		$	46,228		$	46,850
	Gypsum Wallboard		114,852			69,712			6,264
	Paperboard		23,610			25,200			16,988
	Concrete and Aggregates		(4,678	)		(5,388	)		(1,097	)
	Other, net		1,368			(1,232	)		356
	Sub-Total		224,638			134,520			69,361
	Corporate General and Administrative		(24,552	)		(23,918	)		(19,617	)
	Other Corporate Charges		—			(10,683	)		(9,117	)
	Earnings Before Interest and Income Taxes		200,086			99,919			40,627
	Loss on Debt Retirement		—			—			(2,094	)
	Interest Expense, net		(18,282	)		(15,823	)		(16,621	)
	Earnings Before Income Taxes	$	181,804		$	84,096		$	21,912
	Cement Operating Earnings -
	Wholly-Owned	$	51,675		$	13,721		$	18,322
	Joint Ventures		37,811			32,507			28,528
		$	89,486		$	46,228		$	46,850
	Capital Expenditures -
	Cement	$	12,226		$	15,583		$	7,753
	Gypsum Wallboard		4,825			2,682			3,357
	Paperboard		3,354			804			919
	Aggregates		34,719			33,829			13,639
	Concrete		4,117			103			321
	Other, net		249			10			110
		$	59,490		$	53,011		$	26,099
	Depreciation, Depletion and Amortization -
	Cement	$	31,829		$	20,658		$	15,373
	Gypsum Wallboard		20,981			21,045			20,903
	Paperboard		8,716			8,824			8,595
	Aggregates		5,119			3,820			3,365
Concrete		1,793			1,392			1,022
Corporate and Other		1,583			1,111			866
	$	70,021		$	56,850		$	50,124
	As of March 31,
	2014			2013			2012
	(dollars in thousands)
Identifiable Assets
Cement	$	762,578		$	756,158		$	313,559
Gypsum Wallboard		412,566			425,866			434,967
Paperboard		125,045			129,226			137,483
Aggregates		152,728			108,796			49,009
Concrete		26,835			27,187			12,031
Other, net		31,777			29,000			38,096
	$	1,511,529		$	1,476,233		$	985,145
Segment operating earnings, including the proportionately consolidated 50% interest in the revenues and expenses of the Joint Venture, represent revenues less direct operating expenses, segment depreciation, and segment selling, general and administrative expenses. We account for intersegment sales at market prices. Corporate assets consist primarily of cash and cash equivalents, general office assets and miscellaneous other assets.
The basis used to disclose Identifiable Assets, Capital Expenditures and Depreciation, Depletion conforms with the equity method, and is similar to how we disclose these accounts in our Consolidated Balance Sheets and Consolidated Statements of Earnings.
The segment breakdown of goodwill at March 31, 2014 and 2013 is as follows:
	For the Years Ended
	March 31,
	2014			2013
	(dollars in thousands)
Cement	$	8,359		$	8,359
Gypsum Wallboard		116,618			116,618
Paperboard		7,538			7,538
	$	132,515		$	132,515
During fiscal 2012, we provided approximately $12.0 million to our Joint Venture for its capital needs, which has been offset against distributions received from the Joint Venture during fiscal 2012 on the Consolidated Statement of Cash Flows.

Income_Taxes

Income Taxes	12 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	(H) Income Taxes
	The provision for income taxes includes the following components:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Current Provision (Benefit) -
	Federal	$	49,604		$	19,108		$	812
	State		2,211			1,089			180
			51,815			20,197			992
	Deferred Provision (Benefit) -
	Federal		7,691			5,173			1,984
	State		(1,945	)		982			204
			5,746			6,155			2,188
	Provision for Income Taxes	$	57,561		$	26,352		$	3,180
	The effective tax rates vary from the federal statutory rates due to the following items:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Earnings Before Income Taxes	$	181,804		$	84,096		$	21,912
	Income Taxes at Statutory Rate	$	63,631		$	29,434		$	7,669
	Increases (Decreases) in Tax Resulting from -
	State Income Taxes, net		173			1,346			249
	Statutory Depletion in Excess of Cost		(3,512	)		(3,110	)		(2,619	)
	Domestic Production Activities Deduction		(3,453	)		(1,895	)		36
	Meals and Entertainment Disallowance		503			337			284
	Penalties on Uncertain Tax Positions		213			215			190
	Tax Benefits-ASC 740 Accruals and State Amnesty Programs		—			(42	)		(2,558	)
	Other		6			67			(71	)
	Provision for Income Taxes	$	57,561		$	26,352		$	3,180
	Effective Tax Rate		32	%		31	%		15	%
	During fiscal 2012, the Federal statute of limitations for assessment for the years ended March 31, 2004, March 31, 2005 and March 31, 2006 expired. Also, we participated in amnesty programs in Arizona, Colorado and California. These events were treated as discrete items in the tax provision and a benefit totaling $2.5 million on an after-tax basis was recognized.
	The deferred income tax provision results from the following temporary differences in the recognition of revenues and expenses for tax and financial reporting purposes:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Excess Tax Depreciation and Amortization	$	6,875		$	7,038		$	4,617
	Bad Debts		(224	)		(73	)		(119	)
	Uniform Capitalization		(1,127	)		(14	)		(1,004	)
	Accrual Changes		(1,075	)		(1,169	)		1,107
	Uncertain Tax Position Accruals		213			173			(2,264	)
	Prepaid Insurance		424			—			—
	Other		660			200			(149	)
		$	5,746		$	6,155		$	2,188
	Components of deferred income taxes are as follows:
		March 31,
		2014			2013
		(dollars in thousands)
	Items Giving Rise to Deferred Tax Liabilities -
	Excess Tax Depreciation and Amortization	$	(144,619	)	$	(142,343	)
	Repair Parts		(4,545	)		(3,827	)
	State Income Taxes		(7,648	)		(8,967	)
	Other		(4,997	)		(4,277	)
	Total Deferred Tax Liabilities	$	(161,809	)	$	(159,414	)
	Items Giving Rise to Deferred Tax Assets -
	Accrual Changes	$	9,946		$	13,352
	Bad Debts		2,122			1,898
	Uniform Capitalization		2,131			1,004
	Other		2,398			4,321
	Total Deferred Tax Assets	$	16,597		$	20,575
	Deferred income taxes are classified in the consolidated balance sheet as follows:
		March 31,
		2014			2013
		(dollars in thousands)
Prepaid and Other Assets		561			189
Deferred Income Taxes	$	(145,773	)	$	(139,028	)
Uncertain tax position –
We are subject to audit examinations at federal, state and local levels by tax authorities in those jurisdictions who may challenge the treatment or reporting of any return item. The tax matters challenged by the tax authorities are typically complex; therefore, the ultimate outcome of these challenges is subject to uncertainty.
Reconciliation of the consolidated liability for gross unrecognized tax benefits, excluding interest, from April 1, 2011 to March 31, 2014, is as follows:
	For the Years Ended March 31,
	2014			2013			2012
	(dollars in thousands)
Balance at Beginning of Year	$	24,589		$	25,890		$	28,450
Increase related to prior tax positions		213			215			534
Decrease related to prior tax positions		—			(1,516	)		(2,797	)
Payments		—			—			(297	)
	$	24,802		$	24,589		$	25,890
We recognize penalties associated with uncertain tax positions as part of the tax provision, while interest associated with uncertain tax positions is included in interest expense. The following is a summary of the amounts of interest and penalties recognized in relation to our uncertain tax position:
	For the Years Ended March 31,
	2014			2013			2012
	(dollars in thousands)
Accrued interest recognized	$	641		$	409		$	(903	)
Accrued penalties recognized	$	213		$	173		$	190
Accrued interest related to our uncertain tax positions totaled $4.4 million and $3.8 million at March 31, 2014 and 2013, respectively, while accrued penalties totaled $3.2 million and $3.0 million at March 21, 2014, and 2013, respectively. The amount of net unrecognized tax benefits that, if recognized, would affect the effective tax rate at March 31, 2014 was $24.8 million, of which $14.9 million has been deducted on our tax returns.
In May 2011, we filed a lawsuit against the Internal Revenue Service (“IRS”) in Federal District Court to recover all of the amounts paid to the IRS with respect to our uncertain tax position for 2001 to 2006. If we were to prevail, we would receive a refund of up to $106.6 million related to federal and state taxes, interest and penalties paid since fiscal 2008. Any refund of income taxes or penalties received from the IRS would be recorded as a tax benefit and impact our effective tax rate. Any refund of interest would reduce future interest expense. Additionally, we would reduce other long-term liabilities by $29.2 million, which is comprised of $24.8 million related to our unrecognized tax benefit, including penalties, and $4.4 for accrued interest on the uncertain tax position, which would also impact our tax provision.
In March 2013, the IRS agreed to suspend the audit for tax years 2007 through 2011 pending the outcome of our case before the Federal District Court. See Footnote (I), Commitments and Contingencies, for more information about the lawsuit against the IRS.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Mar. 31, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	(I) Commitments and Contingencies
	Our operations and properties are subject to extensive and changing federal, state and local laws, regulations and ordinances governing the protection of the environment, as well as laws relating to worker health and workplace safety. We carefully consider the requirements mandated by such laws and regulations and have procedures in place at all of our operating units to monitor compliance. Any matters which are identified as potential exposures under these laws and regulations are carefully reviewed by management to determine our potential liability. Although management is not aware of any exposures which require an accrual under generally accepted accounting principles, there can be no assurance that prior or future operations will not ultimately result in violations, claims or other liabilities associated with these regulations.
	We have certain deductible limits under our workers’ compensation and liability insurance policies for which reserves are established based on the estimated costs of known and anticipated claims. We have entered into standby letter of credit agreements to secure funding obligations on retentions relating to workers’ compensation and auto and general liability self-insurance. At March 31, 2014, we had contingent liabilities under these outstanding letters of credit of approximately $7.4 million.
	We are currently contingently liable for performance under $16.0 million in performance bonds required by certain states and municipalities, and their related agencies. The bonds are principally for certain reclamation obligations and mining permits. We have indemnified the underwriting insurance company against any exposure under the performance bonds. In our past experience, no material claims have been made against these financial instruments.
	Outstanding Lawsuit against the IRS
	As previously reported, the Internal Revenue Service (the “IRS”) completed the examination of our federal income tax returns for all of the fiscal years ended March 31, 2001 through 2006. The IRS issued Exam Reports and Notices of Proposed Adjustment on November 9, 2007 for the examination of the 2001, 2002 and 2003 tax years, and on February 5, 2010 for the examination of the 2004, 2005 and 2006 fiscal years, in which it denied certain depreciation deductions claimed by us with respect to assets acquired by us from Republic Group LLC in November 2000. We paid a deposit to the IRS of approximately $45.8 million during November 2007 for the years ended March 31, 2001, 2002 and 2003, which is comprised of $27.6 million in federal income taxes, $5.7 million for penalties and $12.5 million for interest. During March 2010, we paid the IRS an additional deposit of $29.3 million for the years ended March 31, 2004, 2005 and 2006, which is comprised of $18.1 million in federal income taxes, $3.7 million for penalties and $7.5 million for interest. These deposits were made to avoid imposition of the large corporate tax underpayment interest rates. On June 29, 2010 we received a Notice of Deficiency (commonly referred to as a “90 day letter”) and shortly thereafter converted the previously made deposits to tax, penalty and interest paid and paid an additional $23.6 million comprised of $13.6 million of tax, $2.9 million of penalties and $7.1 million of interest. Subsequent reviews of IRS interest computations resulted in a $0.8 million dollar refund which reduced the total net payment to $97.9 million. On May 4, 2011, we filed a lawsuit in Federal District Court to recover the $97.9 million of taxes, penalties and interest ultimately paid. In September 2013, the judge heard arguments on each party’s motion for summary judgment and in November of 2013 the judge denied each such motion. The judge scheduled the trial for September 2014.
	At this time we are unable to predict with certainty the ultimate outcome or how much of the amounts paid for tax, interest and penalties to the IRS and state taxing authorities will be recovered, if any. In the event we reach a settlement through negotiation or in the courts, we will reverse any amounts in excess of the settlement through the Consolidated Statement of Earnings in the period such settlement is reached.
	EPA Notice of Violation
	On October 5, 2010, Region IX of the EPA issued a Notice of Violation and Finding of Violation (“NOV”) alleging violations by our subsidiary, Nevada Cement Company (“NCC”), of the Clean Air Act (“CAA”). The NOV alleges that NCC made certain physical changes to its facility in the 1990s without first obtaining permits required by the Prevention of Significant Deterioration requirements and Title V permit requirements of the CAA. The EPA also alleges that NCC has failed to submit to EPA since 2002 certain reports as required by the National Emissions Standard for Hazardous Air Pollutants General Provisions and the Portland Cement Manufacturing Industry Standards. On March 12, 2014, EPA Region IX issued a second NOV to NCC. The second NOV is materially similar to the 2010 NOV except that it alleges violations of the new source performance standards (“NSPS”) for portland cement plants. The NOVs state that the EPA may seek penalties although it does not propose or assess any specific level of penalties or specify what relief the EPA will seek for the alleged violations. NCC believes it has meritorious defenses to the allegations in the NOVs. NCC met with the EPA in December 2010, September 2012 and May 2014 to present its defenses and to discuss a resolution of the alleged violations. EPA and NCC remain in discussions regarding the alleged violations. If a negotiated settlement cannot be reached, NCC intends to vigorously defend these matters in any enforcement action that may be pursued by the EPA. As a part of a settlement, or should NCC fail in its defense in any enforcement action, NCC could be required to make substantial capital expenditures to modify its facility and incur increased operating costs. NCC could also be required to pay significant civil penalties. Additionally, an enforcement action could take many years to resolve the underlying issues alleged in the NOV. We are currently unable to determine the final outcome of this matter or the impact of an unfavorable determination upon our financial position or results of operations.
	Domestic Wallboard Antitrust Litigation
	Since late December 2012, several purported class action lawsuits were filed against the Company’s subsidiary, American Gypsum Company LLC (“American Gypsum”), alleging that American Gypsum conspired with other wallboard manufacturers to fix the price for drywall sold in the United States in violation of federal antitrust laws and, in some cases related provisions of state law. The complaints allege that the defendant wallboard manufacturers conspired to increase prices through the announcement and implementation of coordinated price increases, output restrictions, and other restraints of trade, including the elimination of individual “job quote” pricing. In addition to American Gypsum, the defendants in these lawsuits include CertainTeed Corp., USG Corporation, New NGC, Inc., Lafarge North America, Georgia-Pacific LLC, Temple Inland Inc. and PABCO Building Products LLC. The plaintiffs in these class action lawsuits bring claims on behalf of purported classes of direct or indirect purchasers of wallboard during various periods from 2008 to present for unspecified monetary damage (including treble damages) and in some cases injunctive relief in various United States district courts, including the Eastern District of Pennsylvania, Western District of North Carolina, North Carolina and the Northern District of Illinois. On April 8, 2013, the Judicial Panel on Multidistrict Litigation transferred and consolidated all related cases to the Eastern District of Pennsylvania for coordinated pretrial proceedings.
	On June 24, 2013, the direct and indirect purchaser plaintiffs filed consolidated amended class action complaints. The direct purchasers’ complaint added the Company as a defendant. On July 29, 2013, the Company and American Gypsum answered the complaints, denying all allegations that they conspired to increase the price of drywall and asserting affirmative defenses to plaintiffs’ claims.
	While American Gypsum’s production of written discovery is substantially complete, discovery is ongoing. Due to the fact that these claims remain in a preliminary phase, and the plaintiffs have not specified the amount of any damages they are seeking, we are unable to estimate the amount of any reasonably possible loss or range of reasonably possible losses. American Gypsum denies the allegations in these lawsuits and will vigorously defend itself against these claims.
	Arbitration Claim
	In June 2011, we were served with a claim for arbitration involving a contract dispute between one of our aggregates mining subsidiaries and another mining company over the right to mine certain areas. The mining company which brought this claim mines gold in the same area in which our subsidiary mines aggregates. The dispute centered on two agreements entered into by the parties in 1989 and 1992 that address the rights and obligations of the parties with respect to the areas in which both companies mine. In the arbitration, the gold mining company claimed that our subsidiary’s operations in a limited area (which are conducted through a licensee) interfered with the gold mining company’s right under the agreements to mine gold and that the gold in that area was therefore no longer recoverable.
	The arbitration panel convened in November 2011 and resulting proceeding was concluded in December 2011, although the decision was not announced until January 19, 2012. The arbitration panel ruled against us and awarded $6.9 million to the other mining company plus attorneys’ fees and arbitration costs to the other party of approximately $1.2 million. All amounts were paid during February 2012. This amount, together with our legal expenses incurred defending this claim, is classified as Acquisition and Litigation Expense in our Consolidated Statements of Earnings for the fiscal year ended March 31, 2012. The ruling involves a limited area within our California aggregates deposit and is not expected to have a material adverse impact on our continuing operations in future periods.
	Other
	In the ordinary course of business, we execute contracts involving indemnifications that are standard in the industry and indemnifications specific to a transaction such as the sale of a business. These indemnifications might include claims relating to any of the following: environmental and tax matters; intellectual property rights; governmental regulations and employment-related matters; customer, supplier, construction contractor and other commercial contractual relationships; and financial matters. While the maximum amount to which we may be exposed under such agreements cannot be estimated, it is the opinion of management that these indemnifications are not expected to have a material adverse effect on the Company’s consolidated financial position, results of operations or cash flows. We currently have no outstanding guarantees of third party debt.
	Our paperboard operation, Republic Paperboard Company LLC (“Republic”), is a party to a long-term variable-priced paper supply agreement with St. Gobain pursuant to which Republic is obligated to sell to St. Gobain at least 90% of the gypsum-grade recycled paperboard requirements for three of St. Gobain’s wallboard plants. This comprises approximately 15% to 20% of Republic’s current annual output of gypsum-grade recycled paperboard.
	We have certain forward purchase contracts, primarily for natural gas, that expire during calendar 2014. The contracts are for approximately 25% of our anticipated natural gas usage.
	We have certain operating leases covering manufacturing, transportation and certain other facilities and equipment. Rental expense for fiscal years 2014, 2013 and 2012 totaled $3.2 million, $1.6 million and $1.7 million, respectively. Minimum annual rental commitments as of March 31, 2014, under noncancellable leases are set forth as follows (dollars in thousands):
	Fiscal Year	Amount
	2015	$	3,155
	2016	$	2,829
	2017	$	2,617
	2018	$	2,004
	2019	$	2,003
	Thereafter	$	4,731

Stock_Option_Plans

Stock Option Plans	12 Months Ended
	Mar. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock Option Plans	'
	(J) Stock Option Plans
	On August 7, 2013 our stockholders approved the Eagle Materials Inc. Amended and Restated Incentive Plan (the “Plan”), which increased the shares we are authorized to issue as awards by 3,000,000 (1,500,000 of which may be stock awards). Under the terms of the Plan, we can issue equity awards, including stock options, restricted stock units (“RSUs”), restricted stock and stock appreciation rights to employees of the Company and members of the Board of Directors. Awards that were already outstanding prior to the approval of the Plan on August 7, 2013 remain outstanding. The Compensation Committee of our Board of Directors specifies the terms for grants of equity awards under the Plan.
	Long-Term Compensation Plans –
	Options. In August 2013, the Compensation Committee of the Board of Directors approved an incentive equity award of an aggregate of 206,914 stock options pursuant to the Plan to certain officers and key employees that vest ratably over a three year period (the “Fiscal 2014 Employee Stock Option Grant”). The options have a term of ten years from the date of grant. In August 2013, we granted 30,075 options to members of the Board of Directors (the “Fiscal 2014 Board of Directors Grant”). Options granted under the Fiscal 2014 Board of Directors Grant vest immediately and can be exercised from the date of grant until their expiration on the tenth anniversary of the date of grant. The Fiscal 2014 Employee Stock Option Grant and Fiscal 2014 Board of Directors Grant were valued at the grant date using the Black-Scholes option pricing model.
	All stock options issued during fiscal 2014 and 2013 were valued at the grant date using the Black-Scholes option pricing model. The weighted-average assumptions used in the Black-Scholes model to value the option awards in fiscal 2014 and 2013 are as follows:
		2014			2013
	Dividend Yield		2	%		2	%
	Expected Volatility		44.6	%		44.1	%
	Risk Free Interest Rate		2.04	%		1.7	%
	Expected Life		7.0 years			7.9 years
	Stock option expense for all outstanding stock option awards was approximately $5.3 million, $4.0 million and $1.4 million, for the years ended March 31, 2014, 2013 and 2012, respectively. The expense for 2012 reflects credits of $1.3 million, resulting from our updated assessment of future compliance with performance conditions associated with certain stock option grants. At March 31, 2014, there was approximately $8.2 million of unrecognized compensation cost related to outstanding stock options which is expected to be recognized over a weighted-average period of 2.0 years.
	The following table represents stock option activity for the years presented:
		For the Years Ended March 31,
		2014						2013					2012
		Number			Weighted			Number			Weighted		Number			Weighted
		of			Average			of			Average		of			Average
		Shares			Exercise			Shares			Exercise		Shares			Exercise
					Price						Price					Price
	Outstanding Options at Beginning of Year		3,022,592		$	37.83			3,241,322		$	36.11		3,323,786		$	35.6
	Granted		256,989		$	68			569,679		$	34.64		474,124		$	26.41
	Exercised		(485,582	)	$	29.72			(746,131	)	$	27.64		(383,811	)	$	18.57
	Cancelled		(5,000	)	$	53.22			(42,278	)	$	42.21		(172,777	)	$	38.69
	Outstanding Options at End of Year		2,788,999		$	41.83			3,022,592		$	37.83		3,241,322		$	36.11
	Options Exercisable at End of Year		818,215						986,187					1,567,734
	Weighted Average Fair Value of Options Granted during the Year				$	26.35					$	13.28				$	10.29
	The following table summarizes information about stock options outstanding at March 31, 2014:
		Options Outstanding									Options Exercisable
	Range of Exercise Prices	Number of			Weighted			Weighted			Number of		Weighted
		Shares			Average			Average			Shares		Average
		Outstanding			Remaining			Exercise			Outstanding		Exercise
					Contractual			Price					Price
					Life
	$23.17 - $30.74		679,191			5.02		$	26.5			559,762	$	26.26
	$33.08 - $40.78		558,000			7.24		$	34.4			206,274	$	35.13
	$47.53 - $87.34		1,551,808			1.86		$	51.21			52,179	$	65.2
			2,788,999			3.7		$	41.83			818,215	$	30.98
	At March 31, 2014, the aggregate intrinsic value for outstanding and exercisable options was approximately $130.6 million and $47.2 million, respectively. The total intrinsic value of options exercised during the fiscal year ended March 31, 2014 was approximately $22.1 million.
	Restricted Stock Units. Expense related to RSUs was approximately $1.6 million and $1.5 million in fiscal years ended March 31, 2013 and 2012, respectively. There was no expense related to RSUs for the fiscal year ended March 31, 2014. At March 31, 2014, there were approximately 20,000 unvested RSUs, with approximately $0.1 million of unearned compensation, net of estimated forfeitures, which will be recognized over a weighted-average period of 2.0 years.
	Restricted Stock. In August 2013, the Compensation Committee also approved the granting of an aggregate of 93,186 shares of restricted stock to certain key employees at both the corporate and subsidiary level (the “Fiscal 2014 Employee Restricted Stock Award”) that will be earned if our ten year return on equity is at least 15% at March 31, 2014. If this criterion is not met, all of the shares will be forfeited. If the criterion is met, the award may be reduced by the Compensation Committee based on individual performance goals. The Compensation Committee has certified that the performance criterion was met at March 31, 2014; therefore, all shares were earned. Restriction on the shares will lapse ratably over five years. The first fifth lapsed on May 9, 2014, and the remaining restrictions lapsing on March 31, 2015 through 2018. The value of the Fiscal 2014 Employee Restricted Stock Award, net of estimated forfeitures, is being expensed over a five year period. In August 2013, we granted 5,761 shares of restricted stock to members of the Board of Directors (the “Board of Directors Fiscal 2014 Restricted Stock Award”). Awards issued under the Board of Directors Fiscal 2014 Restricted Stock Award do not fully vest until the retirement of each director, in accordance with the Company’s director retirement policy.
	Expense related to restricted shares was $4.8 million, $3.4 million and $2.6 million in fiscal years ended March 31, 2014, 2013 and 2012, respectively. At March 31, 2014, there were approximately 560,000 shares with remaining restrictions for which $15.0 million of unearned compensation, net of estimated forfeitures, will be recognized over a weighted-average period of 3.2 years.
	The number of shares available for future grants of stock options, restricted stock units, stock appreciation rights and restricted stock under the Plan was 3,981,878 at March 31, 2014. Of the available shares, up to 1,538,021 can be used for future restricted stock and restricted stock unit grants.

Net_Interest_Expense

Net Interest Expense	12 Months Ended
	Mar. 31, 2014
Banking And Thrift Interest [Abstract]	'
Net Interest Expense	'
	(K) Net Interest Expense
	The following components are included in interest expense, net:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Interest Income	$	(5	)	$	(53	)	$	(6	)
	Interest Expense		16,751			14,769			16,969
	Interest Expense (Income) – IRS		641			409			(903	)
	Other Expenses		895			698			561
	Interest Expense, net	$	18,282		$	15,823		$	16,621
	Interest income includes interest on investments of excess cash. Components of interest expense include interest associated with the Senior Notes, Credit Facility and commitment fees based on the unused portion of the Credit Facility. Other expenses include amortization of debt issuance costs, and bank credit facility costs.
	Interest expense (income) – IRS relates to interest accrued on our unrecognized tax benefits, primarily related to the Republic Asset Acquisition. During fiscal 2012, we reversed previously accrued interest expense for certain matters for which the statute of limitations had expired.

Pension_and_Profit_Sharing_Pla

Pension and Profit Sharing Plans	12 Months Ended
	Mar. 31, 2014
Compensation And Retirement Disclosure [Abstract]	'
Pension and Profit Sharing Plans	'
	(L) Pension and Profit Sharing Plans
	We have several defined benefit and defined contribution retirement plans which together cover substantially all of our employees. Benefits paid under the defined benefit plans covering certain hourly employees are based on years of service and the employee’s qualifying compensation over the last few years of employment. Our funding policy is to generally contribute amounts that are deductible for income tax purposes. The annual measurement date is March 31 for the benefit obligations, fair value of plan assets and the funded status of the defined benefit plans.
	The following table provides a reconciliation of the obligations and fair values of plan assets for all of our defined benefit plans over the two year period ended March 31, 2014 and a statement of the funded status as of March 31, 2014 and 2013:
		For the Years Ended
		March 31,
		2014			2013
		(dollars in thousands)
	Reconciliation of Benefit Obligations -
	Benefit Obligation at April 1,	$	29,586		$	24,735
	Service Cost - Benefits Earned During the Period		1,129			785
	Interest Cost on Projected Benefit Obligation		1,222			1,222
	Actuarial (Gain) Loss		(1,237	)		3,576
	Benefits Paid		(808	)		(732	)
	Benefit Obligation at March 31,	$	29,892		$	29,586
	Reconciliation of Fair Value of Plan Assets -
	Fair Value of Plan Assets at April 1,	$	18,693		$	17,310
	Actual Return on Plan Assets		1,735			1,598
	Employer Contributions		1,569			517
	Benefits Paid		(808	)		(732	)
	Fair Value of Plans at March 31,		21,189			18,693
	Funded Status -
	Unfunded Status at March 31,	$	(8,703	)	$	(10,893	)
	Amounts Recognized in the Balance Sheet Consist of -
	Accrued Benefit Liability	$	(8,703	)	$	(10,893	)
	Accumulated Other Comprehensive Losses:
	Net Actuarial Loss		8,419			10,812
	Prior Service Cost		15			22
	Accumulated Other Comprehensive Losses	$	8,434		$	10,834
	Tax impact		(2,952	)		(3,792	)
	Accumulated Other Comprehensive Losses, net of tax	$	5,482		$	7,042
	Information for pension plans with an accumulated benefit obligation in excess of plan assets:
		March 31,
		2014			2013
		(dollars in thousands)
	Projected Benefit Obligation	$	29,892		$	29,586
	Accumulated Benefit Obligation	$	29,827		$	29,497
	Fair Value of Plan Assets	$	21,189		$	18,693
	Net periodic pension cost for the fiscal years ended March 31, 2014, 2013 and 2012, included the following components:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Service Cost - Benefits Earned During the Period	$	1,129		$	785		$	561
	Interest Cost of Projected Benefit Obligation		1,222			1,222			1,104
	Expected Return on Plan Assets		(1,506	)		(1,371	)		(1,293	)
	Recognized Net Actuarial Loss		921			980			242
	Amortization of Prior-Service Cost		11			21			33
	Net Periodic Pension Cost	$	1,777		$	1,637		$	647
	Expected benefit payments over the next five years, and the following five years under the pension plans are expected to be as follows (in thousands):
	Fiscal Years	Total
	2015	$	978
	2016	$	1,065
	2017	$	1,113
	2018	$	1,184
	2019	$	1,280
	2020-2024	$	8,307
	The following table sets forth the assumptions used in the actuarial calculations of the present value of net periodic benefit cost and benefit obligations:
		March 31,
		2014			2013			2012
	Net Periodic Benefit Costs -
	Discount Rate		4.2	%		4.56	%		5.61	%
	Expected Return on Plan Assets		8	%		8	%		8	%
	Rate of Compensation Increase		3.5	%		3.5	%		3.5	%
		March 31,
	2014			2013
Benefit Obligations -
Discount Rate		4.41	%		4.2	%
Rate of Compensation Increase		3.5	%		3.5	%
The expected long-term rate of return on plan assets is an assumption reflecting the anticipated weighted-average rate of earnings on the portfolio over the long-term. To arrive at this rate, we developed estimates of the key components underlying capital asset returns including: market-based estimates of inflation, real risk-free rates of return, yield curve structure, credit risk premiums and equity risk premiums. As appropriate, these components were used to develop benchmark estimates of the expected long-term management approach employed by us, and a return premium was added to the weighted-average benchmark portfolio return.
The pension plans’ approximate weighted-average asset allocation at March 31, 2014 and 2013 and the range of target allocation are as follows:
	Range of			Percentage of
	Target			Plan
				Assets at
				March 31,
	Allocation			2014			2013
Asset Category -
Equity Securities		40 – 60	%		65	%		60	%
Debt Securities		35 – 60	%		30	%		30	%
Other		0 – 5	%		5	%		10	%
Total					100	%		100	%
Our pension investment strategies have been developed as part of a comprehensive asset/liability management process that considers the interaction between both the assets and liabilities of the plan. These strategies consider not only the expected risk and returns on plan assets, but also the detailed actuarial projections of liabilities as well as plan-level objectives such as projected contributions, expense and funded status.
The principal pension investment strategies include asset allocation and active asset management. The range of target asset allocations have been determined after giving consideration to the expected returns of each asset class, the expected variability or volatility of the asset class returns over time, and the complementary nature or correlation of the asset classes within the portfolio. We also employ an active management approach for the portfolio. Each asset class is managed by one or more external money managers with the objective of generating returns, net of management fees that exceed market-based benchmarks. None of the plans hold any EXP stock.
Based on our current actuarial estimates, we anticipate making contributions ranging from approximately $0.5 million to $1.0 million to our defined benefit plans for fiscal year 2015.
The fair values of our defined benefit plans’ consolidated assets by category as of March 31, 2014 and 2013 were as follows:
	March 31,
	2014			2013
	(dollars in thousands)
Equity Securities	$	13,973		$	12,034
Fixed Income Securities		6,526			5,752
Real Estate Funds		130			287
Commodity Linked Funds		170			420
Cash Equivalents		390			200
Total	$	21,189		$	18,693
The fair values of our defined benefit plans’ consolidated assets were determined using the fair value hierarchy of inputs described in Note (A).
The fair values by category of inputs as of March 31, 2014 were as follows:
Asset Categories	Quoted Prices in			Significant			Significant			Total
	Active Markets			Other			Unobservable
	for Identical			Observable			Inputs
	Assets			Inputs			(Level 3)
	(Level 1)			(Level 2)
	(dollars in thousands)
Equity Securities	$	—		$	13,973		$	—		$	13,973
Fixed Income Securities		—			6,526			—			6,526
Real Estate Funds		—			130			—			130
Commodity Linked Funds		—			170			—			170
Cash Equivalents		390			—			—			390
	$	390		$	20,799		$	—		$	21,189
The fair values by category of inputs as of March 31, 2013 were as follows:
Asset Categories	Quoted Prices in			Significant			Significant			Total
	Active Markets			Other			Unobservable
	for Identical			Observable			Inputs
	Assets			Inputs			(Level 3)
	(Level 1)			(Level 2)
	(dollars in thousands)
Equity Securities	$	—		$	12,034		$	—		$	12,034
Fixed Income Securities		—			5,752			—			5,752
Real Estate Funds		—			287			—			287
Commodity Linked Funds		—			420			—			420
Cash Equivalents		200			—			—			200
	$	200		$	18,493		$	—		$	18,693
Equity securities consist of funds that are not actively traded. These funds are maintained by an investment manager and are primarily invested in indexes. The remaining funds, excluding cash, primarily consist of investments in institutional funds.
We also provide profit sharing plans, which cover substantially all salaried and certain hourly employees. The profit sharing plan is a defined contribution plan funded by employer discretionary contributions and also allows employees to contribute a certain percentage of their base annual salary. Employees are fully vested to the extent of their contributions and become fully vested in any Company contributions over a six year period for salaried employees and a three year period for hourly employees. Costs relating to the employer discretionary contributions for our contribution plan totaled $4.5 million, $3.3 million and $2.5 million in fiscal years 2014, 2013 and 2012, respectively.
Employees who became employed by us as a result of a previous transaction are provided benefits substantially comparable to those provided under the seller’s benefit plans. These plans included the seller’s 401(k) plan which included employer matching percentages for hourly employees. As a result, we made matching contributions to the hourly profit sharing plan totaling $0.2 million, $0.1 million and $0.1 million for these employees during fiscal years 2014, 2013 and 2012, respectively.
As part of the Acquisition, we became party to certain multi-employer pension plans and health and welfare plans. Approximately sixty of our employees belong to five different multi-employer plans. The collective bargaining agreements for the employees who participate in the multi-employer plans expire between June 2014 and March 2017. Our expense related to these plans was approximately $1.0 million and $0.2 million during fiscal years 2014 and 2013, respectively. We anticipate the total expense in fiscal 2015 related to these plans will be approximately $1.0 million.

Quarterly_Results_unaudited

Quarterly Results (unaudited)	12 Months Ended
	Mar. 31, 2014
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Results (unaudited)	'
	(M) Quarterly Results (unaudited)
		For the Years Ended March 31,
		2014		2013
		(dollars in thousands, except per share data)
	First Quarter -
	Revenues	$	227,044	$	154,042
	Gross Profit		46,604		22,897
	Earnings Before Income Taxes		44,516		19,914
	Net Earnings		30,101		13,978
	Diluted Earnings Per Share	$	0.6	$	0.31
	Second Quarter -
	Revenues	$	252,646	$	164,659
	Gross Profit		59,479		32,489
	Earnings Before Income Taxes		58,688		26,125
	Net Earnings		39,903		17,953
	Diluted Earnings Per Share	$	0.8	$	0.4
	Third Quarter -
	Revenues	$	228,812	$	164,743
	Gross Profit		49,848		31,261
	Earnings Before Income Taxes		48,833		27,301
	Net Earnings		31,621		17,980
	Diluted Earnings Per Share	$	0.63	$	0.37
	Fourth Quarter -
	Revenues	$	189,894	$	159,118
	Gross Profit		29,528		16,598
	Earnings Before Income Taxes		29,767		10,756
	Net Earnings		22,618		7,833
	Diluted Earnings Per Share	$	0.45	$	0.16
	The fourth quarter of fiscal 2014 was adversely impacted by the annual maintenance outage of approximately $4.5 million at our Illinois cement plant. This outage has historically occurred in April or May of the fiscal year. The fourth quarter of fiscal 2014 was also adversely impacted by approximately $1.3 million in legal costs, $1.5 million in maintenance, and $0.9 million in increased natural gas costs for our gypsum wallboard business. The increase in maintenance costs was due to the timing of certain major maintenance projects, while the increase in natural gas was due to increased market prices.
	The fourth quarter of fiscal 2013 includes approximately $14.0 million of repair and maintenance expense at our two new cement facilities. This expense was incurred during extended outages at each plant, and consisted primarily of standard maintenance and repairs. Additionally, we incurred acquisition and litigation expenses of approximately $2.4 million related to the Acquisition and our lawsuit against the IRS, as disclosed in Note (B), Acquisition, and Note (I), Commitments and Contingencies.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation –
	The consolidated financial statements include the accounts of Eagle Materials Inc. and its majority-owned subsidiaries (“EXP” or the “Company”), which may be referred to as “our”, “we”, or “us”. All intercompany balances and transactions have been eliminated. EXP is a holding company whose assets consist of its investments in its subsidiaries, joint venture, intercompany balances and holdings of cash and cash equivalents. The businesses of the consolidated group are conducted through EXP’s subsidiaries. The Company conducts one of its cement plant operations through a joint venture, Texas Lehigh Cement Company L.P., which is located in Buda, Texas (the “Joint Venture”). Investments in the Joint Venture and affiliated companies owned 50% or less are accounted for using the equity method of accounting. The Equity in Earnings of Unconsolidated Joint Venture has been included for the same period as our March 31 year end.
	The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents –
	Cash equivalents include short-term, highly liquid investments with original maturities of three months or less and are recorded at cost, which approximates market value.
Accounts and Notes Receivable	'
	Accounts and Notes Receivable –
	Accounts and notes receivable have been shown net of the allowance for doubtful accounts of $5.8 million and $5.1 million at March 31, 2014 and 2013, respectively. We perform ongoing credit evaluations of our customers’ financial condition and generally require no collateral from our customers. The allowance for non-collection of receivables is based upon analysis of economic trends in the construction industry, detailed analysis of the expected collectability of accounts receivable that are past due and the expected collectability of overall receivables. We have no significant credit risk concentration among our diversified customer base.
	We had notes receivable totaling approximately $9.3 million at March 31, 2014, of which approximately $6.3 million has been classified as current and presented with accounts receivable on the balance sheet. We lend funds to certain companies in the ordinary course of business, and the notes bear interest, on average, at 4.3%, which will vary based on changes to LIBOR. Remaining unpaid amounts, plus accrued interest, mature on various dates between 2014 and 2017. The notes are collateralized by certain assets of the borrowers, namely property and equipment. We monitor the credit risk of each borrower by focusing on the timeliness of payments, review of credit history and credit metrics and interaction with the borrowers. At March 31, 2014 and 2013, approximately $0.3 million of our allowance for doubtful accounts is related to our notes receivable.
Inventories	'
	Inventories –
	Inventories are stated at the lower of average cost (including applicable material, labor, depreciation, and plant overhead) or market. Inventories consist of the following:
		March 31,
		2014			2013
		(dollars in thousands)
	Raw Materials and Materials-in-Progress	$	82,319		$	60,026
	Finished Cement		19,173			18,077
	Gypsum Wallboard		7,144			6,855
	Aggregates		12,090			12,830
	Paperboard		4,102			2,867
	Repair Parts and Supplies		56,119			49,361
	Fuel and Coal		6,149			6,364
		$	187,096		$	156,380
Property, Plant and Equipment	'
	Property, Plant and Equipment –
	Property, plant and equipment are stated at cost. Major renewals and improvements are capitalized and depreciated. Annual maintenance is expensed as incurred. Depreciation is provided on a straight-line basis over the estimated useful lives of depreciable assets and totaled $67.3 million, $55.1 million and $48.9 million for the years ended March 31, 2014, 2013 and 2012, respectively. Raw material deposits are depleted as such deposits are extracted for production utilizing the units-of-production method. Costs and accumulated depreciation applicable to assets retired or sold are eliminated from the accounts and any resulting gains or losses are recognized at such time. The estimated lives of the related assets are as follows:
	Plants		20 to 30 years
	Buildings		20 to 40 years
	Machinery and Equipment		3 to 25 years
	We periodically evaluate whether current events or circumstances indicate that the carrying value of our depreciable assets may not be recoverable. At March 31, 2014 and 2013, management believes no events or circumstances indicate that the carrying value may not be recoverable.
	We temporarily idled our gypsum manufacturing facility in Bernalillo, N.M. beginning in December 2009, due to cyclical low gypsum wallboard demand. The carrying value of the Bernalillo plant and equipment at March 31, 2014 was $2.9 million and $1.6 million, respectively and we continue to depreciate the assets over their estimated useful life. We currently have a strong market position in New Mexico, and our Albuquerque gypsum wallboard facility is operating at close to capacity. We plan on resuming manufacturing at the Bernalillo facility in the future when additional capacity is needed to meet demand for our products. Costs of maintaining the facility during the idling are not significant, and the facility was generating positive cash flow prior to being idled; therefore, we have determined that the value of the plant and equipment is not impaired. We are not currently considering the permanent closure of the Bernalillo facility. Any decision to permanently close Bernalillo would be the result of future changes in the building materials industry in the southwest United States and Rocky Mountain region, including changes in the production capacity or operations of our competitors, demand for gypsum wallboard or general macro-economic conditions, which we do not foresee at the present time. If we were to permanently close the Bernalillo facility, or if our expectations as to its use changed such that we project the future undiscounted cash flows from its operations would be insufficient to recover its carrying value due to the factors described above, or for any other reason, we would recognize impairment at that time.
Impairment or Disposal of Long-Lived and Intangible Assets	'
	Impairment or Disposal of Long-Lived and Intangible Assets –
	We evaluate the recoverability of our long-lived assets and certain identifiable intangibles, such as permits and customer contracts, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets, such as plants, buildings and machinery and equipment, including mining assets, is measured by comparing the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. Such evaluations for impairment are significantly impacted by estimates of future prices for our products, capital needs, economic trends in the construction sector and other factors. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds their fair value. Assets to be disposed of by sale are reflected at the lower of their carrying amount or fair value less cost to sell.
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets –
	Goodwill. Goodwill is subject to at least an annual assessment for impairment by applying a fair-value-based test. We have elected to test for goodwill impairment in the fourth quarter of each fiscal year. The goodwill impairment test is a two-step process, which requires us to make judgments in determining what assumptions to use in the calculation. The first step of the process consists of estimating the fair value of each reporting unit based on a discounted cash flow model using revenues and profit forecasts and comparing those estimated fair values with the carrying value; a second step is performed, if necessary, to compute the amount of the impairment by determining an “implied fair value” of goodwill. Similar to the review for impairment of other long-lived assets, evaluations for impairment are significantly impacted by estimates of future prices for our products, capital needs, economic trends and other factors.
	Intangible Assets: Intangible assets at March 31, 2014 and 2013 consist of the following:
		March 31, 2014
		Amortization			Cost			Accumulated			Net
		Period						Amortization
		(dollars in thousands)
	Intangible Assets Subject to Amortization:
	Customer contracts and relationships		15 years		$	6,060		$	(1,580	)	$	4,480
	Sales contracts		4 years			2,500			(833	)		1,667
	Permits		40 years			27,240			(5,212	)		22,028
	Goodwill					132,515			—			132,515
	Total intangible assets and goodwill				$	168,315		$	(7,625	)	$	160,690
		31-Mar-13
		Amortization			Cost			Accumulated			Net
		Period						Amortization
		(dollars in thousands)
	Intangible Assets Subject to Amortization:
	Customer contracts and relationships		15 years		$	6,060		$	(1,176	)	$	4,884
	Sales contracts		4 years			2,500			(208	)		2,292
	Permits		40 years			27,240			(4,531	)		22,709
	Goodwill					132,515			—			132,515
	Total intangible assets and goodwill				$	168,315		$	(5,915	)	$	162,400
	Amortization expense of intangibles was $1.7 million, $1.0 million and $0.6 million for the years ended March 31, 2014, 2013 and 2012, respectively. Amortization expense is expected to be approximately $1.7 million per year for fiscal years 2015 and 2016, $1.5 million in fiscal 2017, and $1.0 million for fiscal years 2018 and 2019.
Other Assets	'
	Other Assets –
	Other assets are primarily composed of loan fees and financing costs, deferred expenses, and deposits.
Income Taxes	'
	Income Taxes –
	Income taxes are accounted for using the asset and liability method. Deferred taxes are recognized for the tax consequences of temporary differences by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities. The effect on deferred taxes of a change in tax rates is recognized in earnings in the period that includes the enactment date. In addition, we recognize future tax benefits to the extent that such benefits are more likely than not to be realized.
Stock Repurchases	'
	Stock Repurchases –
	Our Board of Directors has approved the repurchase of a cumulative total of 31,610,605 shares, of which approximately 717,300 shares remain available for repurchase at March 31, 2014. We did not repurchase any shares in the open market during the years ended March 31, 2014, 2013 and 2012.
Revenue Recognition	'
	Revenue Recognition –
	Revenue from the sale of cement, gypsum wallboard, paperboard, concrete and aggregates is recognized when title and ownership are transferred upon shipment to the customer. Fees for shipping and handling are recorded as revenue, while costs incurred for shipping and handling are recorded as expenses.
	We classify amounts billed to customers for freight as revenues and freight costs as cost of goods sold, respectively, in the Consolidated Statements of Earnings. Approximately $113.1 million, $83.2 million and $66.0 million were classified as cost of goods sold in the years ended March 31, 2014, 2013 and 2012, respectively.
	Other income (loss) includes lease and rental income, asset sale income, non-inventoried aggregates sales income, distribution center income and trucking income as well as other miscellaneous revenue items and costs which have not been allocated to a business segment.
Comprehensive Income/Losses	'
	Comprehensive Income/Losses –
	As of March 31, 2014, we have an accumulated other comprehensive loss of $5.5 million, which is net of income taxes of $3.0 million, in connection with recognizing the difference between the fair value of the pension assets and the projected benefit obligation.
Consolidated Cash Flows - Supplemental Disclosures	'
	Consolidated Cash Flows – Supplemental Disclosures –
	Interest payments made during the years ended March 31, 2014, 2013 and 2012 were $17.0 million, $14.6 million and $18.8 million, respectively.
	We made net payments of $41.7 million and $14.8 million for federal and state income taxes in the years ended March 31, 2014 and 2013, respectively, and received a net refund of $8.0 million in the year ended March 31, 2012.
Statements of Consolidated Earnings - Supplemental Disclosures	'
	Statements of Consolidated Earnings – Supplemental Disclosures –
	Maintenance and repair expenses are included in each segment’s costs and expenses. We incurred $ 77.4 million, $61.3 million and $37.6 million in the years ended March 31, 2014, 2013 and 2012, respectively, which is included in Cost of Goods Sold on the Consolidated Statement of Earnings.
	Selling, general and administrative expenses of the operating units are included in Cost of Goods Sold on the Consolidated Statements of Earnings. Corporate general and administrative (“G&A”) expenses include administration, financial, legal, employee benefits and other corporate activities and are shown separately in the consolidated statements of earnings. Corporate G&A also includes stock compensation expense. See Note (J), Stock Option Plans, for more information.
	Total selling, general and administrative expenses for each of the periods are summarized as follows:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Operating Units Selling, G&A	$	50,175		$	39,133		$	27,695
	Corporate G&A		24,552			23,918			19,617
		$	74,727		$	63,051		$	47,312
	During fiscal 2012, we repurchased $88.1 million of our senior debt at a premium, which was recorded inclusive of transaction costs. The amount of the premium plus transaction costs was $2.1 million.
Earnings Per Share	'
	Earnings Per Share –
		For the Years Ended March 31,
		2014			2013			2012
	Weighted-Average Shares of Common Stock Outstanding		49,090,750			46,622,646			44,224,924
	Effect of Dilutive Shares:
	Assumed Exercise of Outstanding Dilutive Options		1,574,491			1,984,563			800,748
	Less Shares Repurchased from Proceeds of Assumed Exercised Options		(1,032,359	)		(1,568,604	)		(652,046	)
	Restricted Stock Units		306,283			301,845			142,355
	Weighted-Average Common Stock and Dilutive Securities Outstanding		49,939,165			47,340,450			44,515,981
	The “Less Shares Repurchased from Proceeds of Assumed Exercised Options” line includes unearned compensation related to outstanding stock options.
	There were 146,696, 1,082,380 and 2,773,279 stock options at an average exercise price of $65.12 per share, $39.65 per share and $42.17 per share that were excluded from the computation of diluted earnings per share for the years ended March 31, 2014, 2013 and 2012, respectively, because such inclusion would have been anti-dilutive.
Fair Value Measures	'
	Fair Value Measures
	Certain assets and liabilities are required to be recorded or disclosed at fair value. The estimated fair values of those assets and liabilities have been determined using market information and valuation methodologies. Changes in assumptions or estimation methods could affect the fair value estimates; however, we do not believe any such changes would have a material impact on our financial condition, results of operations or cash flows. There are three levels of inputs that may be used to measure fair value:
	Level 1 – Quoted prices for identical assets and liabilities in active markets;
	Level 2 – Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data; and
	Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs.
New Accounting Standards	'
	New Accounting Standards –
	There are no recent accounting pronouncements that materially impacted our financial statements during the current year, and we do not expect any accounting pronouncements to impact our financial statements in the next fiscal year.
Acquisition, Litigation and Other Expense	'
	Acquisition, Litigation and Other Expense
	Acquisition and litigation expense consists primarily of expenses incurred during our acquisition, as discussed in Note (B), Acquisition, and significant legal expenses incurred during litigation, primarily litigation involving an ongoing lawsuit against the Internal Revenue Service (“IRS”), and an adverse arbitration ruling in fiscal 2012. See Note (I), Commitments and Contingencies, for more information about the outstanding lawsuit with the IRS and the results of the arbitration ruling.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Schedule Of Inventories	'
	Inventories consist of the following:
		March 31,
		2014			2013
		(dollars in thousands)
	Raw Materials and Materials-in-Progress	$	82,319		$	60,026
	Finished Cement		19,173			18,077
	Gypsum Wallboard		7,144			6,855
	Aggregates		12,090			12,830
	Paperboard		4,102			2,867
	Repair Parts and Supplies		56,119			49,361
	Fuel and Coal		6,149			6,364
		$	187,096		$	156,380
Schedule of Property, Plant and Equipment Estimated Lives	'
	The estimated lives of the related assets are as follows:
	Plants		20 to 30 years
	Buildings		20 to 40 years
	Machinery and Equipment		3 to 25 years
Schedule of Goodwill and Intangible Assets	'
	Intangible assets at March 31, 2014 and 2013 consist of the following:
		March 31, 2014
		Amortization			Cost			Accumulated			Net
		Period						Amortization
		(dollars in thousands)
	Intangible Assets Subject to Amortization:
	Customer contracts and relationships		15 years		$	6,060		$	(1,580	)	$	4,480
	Sales contracts		4 years			2,500			(833	)		1,667
	Permits		40 years			27,240			(5,212	)		22,028
	Goodwill					132,515			—			132,515
	Total intangible assets and goodwill				$	168,315		$	(7,625	)	$	160,690
		31-Mar-13
		Amortization			Cost			Accumulated			Net
		Period						Amortization
		(dollars in thousands)
	Intangible Assets Subject to Amortization:
	Customer contracts and relationships		15 years		$	6,060		$	(1,176	)	$	4,884
	Sales contracts		4 years			2,500			(208	)		2,292
	Permits		40 years			27,240			(4,531	)		22,709
	Goodwill					132,515			—			132,515
	Total intangible assets and goodwill				$	168,315		$	(5,915	)	$	162,400
Schedule of Total Selling, General and Administrative Expenses	'
	Total selling, general and administrative expenses for each of the periods are summarized as follows:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Operating Units Selling, G&A	$	50,175		$	39,133		$	27,695
	Corporate G&A		24,552			23,918			19,617
		$	74,727		$	63,051		$	47,312
Schedule Of Earnings Per Share	'
		For the Years Ended March 31,
		2014			2013			2012
	Weighted-Average Shares of Common Stock Outstanding		49,090,750			46,622,646			44,224,924
	Effect of Dilutive Shares:
	Assumed Exercise of Outstanding Dilutive Options		1,574,491			1,984,563			800,748
	Less Shares Repurchased from Proceeds of Assumed Exercised Options		(1,032,359	)		(1,568,604	)		(652,046	)
	Restricted Stock Units		306,283			301,845			142,355
	Weighted-Average Common Stock and Dilutive Securities Outstanding		49,939,165			47,340,450			44,515,981

Acquisition_Tables

Acquisition (Tables)	12 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Components of Purchase Price Allocation	'
	Based on the fair value of tangible and intangible assets acquired and liabilities assumed the purchase price is allocated as follows:
	Purchase Price Allocation (in thousands)
	Cash and cash equivalents	$	—
	Accounts Receivable		23,432
	Inventories		20,361
	Prepaid and Other Assets		3,511
	Property and Equipment		407,260
	Intangible Assets		12,500
	Accounts Payable		(9,070	)
	Accrued Liabilities		(3,501	)
	Other Long-term Liabilities		(1,060	)
	Total Net Assets		453,433
	Goodwill		—
	Initial Purchase Price	$	453,433
	Final Working Capital Adjustment		(2,734	)
	Final Purchase Price	$	450,699
Summary of Fair Value Estimates of Identifiable Intangible Assets and Weighted-Average Useful Lives	'
	The following table is a summary of the fair value estimates of the identifiable intangible assets (in thousands) and their weighted-average useful lives:
		Weighted			Fair Value
		Average Life
	Customer Relationships		15		$	4,760
	Sales Contracts		4			2,500
	Permits		40			5,240
	Total Intangible Assets				$	12,500
Net Sales and Operating Income of Acquired Assets	'
	The following table presents the net sales and operating income of the Acquired Assets that has been included in our consolidated statement of earnings from November 30, 2012 through March 31, 2013, and for the fiscal year ended March 31, 2014:
		For the Fiscal Year Ended
		March 31,
		2014			2013
		(dollars in thousands)
	Net Sales	$	158,764		$	28,892
	Operating income (loss)	$	25,249		$	(12,531	)
Unaudited Pro Forma Results	'
		For the Fiscal Year Ended
		March 31,
		2013			2012
		(dollars in thousands)
	Revenues	$	792,979		$	660,401
	Net Income	$	71,361		$	7,460
	Earnings per share – basis	$	1.48		$	0.16
	Earnings per share - diluted	$	1.45		$	0.16
	Weighted Average Shares Outstanding:
	Basic		48,352,346			47,647,924
	Diluted		49,070,150			47,965,981

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Mar. 31, 2014
Property Plant And Equipment [Abstract]	'
Schedule of Property, Plant and Equipment	'
	Cost by major category and accumulated depreciation are summarized as follows:
		March 31,
		2014			2013
		(dollars in thousands)
	Land and Quarries	$	171,987		$	154,710
	Plants		1,357,594			1,324,489
	Buildings, Machinery and Equipment		111,263			110,138
	Construction in Progress		20,131			10,655
			1,660,975			1,599,992
	Accumulated Depreciation		(676,924	)		(614,268	)
		$	984,051		$	985,724

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
	Mar. 31, 2014
Payables And Accruals [Abstract]	'
Schedule of Accrued Expenses	'
	Accrued expenses at March 31, 2014 and 2013 consist of the following:
		March 31,
		2014		2013
		(dollars in thousands)
	Payroll and Incentive Compensation	$	12,855	$	11,827
	Benefits		10,158		10,349
	Interest		4,813		4,813
	Property Taxes		2,801		3,235
	Power and Fuel		2,132		3,146
	Legal		1,831		792
	Sales and Use Tax		658		591
	Acquisition Related Expenses		—		2,023
	Other		6,272		4,573
		$	41,520	$	41,349

Indebtedness_Tables

Indebtedness (Tables)	12 Months Ended
	Mar. 31, 2014
Long-Term Debt	'
	Long-term debt consists of the following:
		As of
		March 31,			March 31,
		2014			2013
		(dollars in thousands)
	Bank Credit Facility	$	189,000		$	297,000
	Senior Notes		192,259			192,259
	Total Debt		381,259			489,259
	Less: Current Portion of Long-term Debt		(9,500	)		—
	Long-term Debt	$	371,759		$	489,259
Schedule of Maturities of Long-Term Debt	'
	Our maturities of long-term debt during the next five fiscal years and thereafter are as follows:
	Fiscal Year	Amount
	2015	$	9,500
	2016		246,045
	2017		8,000
	2018		81,214
	2019		—
	Thereafter		36,500
	Total	$	381,259
2005 Note Purchase Agreement [Member]	'
Schedule of Repurchases of Outstanding Tranches	'
	Following these repurchases and maturities, the amounts outstanding for each of the remaining tranches are as follows:
		Principal			Maturity Date		Interest Rate
	Tranche B	$	57.0 million			November 15, 2015		5.38	%
	Tranche C	$	57.2 million			15-Nov-17		5.48	%
2007 Note Purchase Agreement [Member]	'
Schedule of Repurchases of Outstanding Tranches	'
	Following the repurchase, the amounts outstanding for each of the four tranches are as follows:
		Principal			Maturity Date		Interest Rate
	Tranche A	$	9.5 million			October 2, 2014		6.08	%
	Tranche B	$	8.0 million			2-Oct-16		6.27	%
	Tranche C	$	24.0 million			2-Oct-17		6.36	%
	Tranche D	$	36.5 million			2-Oct-19		6.48	%

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Senior Notes	'
	The fair value of our senior notes has been estimated based upon our current incremental borrowing rates for similar types of borrowing arrangements. The fair value of our Senior Notes at March 31, 2014 is as follows:
		Fair Value
		(dollars in
		thousands)
	Series 2005A Tranche B	$	59,526
	Series 2005A Tranche C		60,933
	Series 2007A Tranche A		9,676
	Series 2007A Tranche B		8,624
	Series 2007A Tranche C		26,208
	Series 2007A Tranche D		40,187

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Financial Information Related to Operations by Segment	'
	The following table sets forth certain financial information relating to our operations by segment:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Revenues -
	Cement	$	438,224		$	304,125		$	243,978
	Gypsum Wallboard		387,016			306,529			217,633
	Paperboard		130,178			121,930			118,794
	Concrete and Aggregates		116,465			56,287			45,515
			1,071,883			788,871			625,920
	Less: Intersegment Revenues		(62,094	)		(49,987	)		(44,757	)
	Less: Joint Venture Revenues		(111,393	)		(96,322	)		(86,140	)
		$	898,396		$	642,562		$	495,023
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Intersegment Revenues -
	Cement	$	8,952		$	2,850		$	3,605
	Paperboard		52,119			46,393			40,485
	Concrete and Aggregates		1,023			744			667
		$	62,094		$	49,987		$	44,757
	Cement Sales Volumes (M tons) -
	Wholly-Owned		3,580			2,390			1,857
	Joint Venture		1,013			913			866
			4,593			3,303			2,723
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Operating Earnings -
	Cement	$	89,486		$	46,228		$	46,850
	Gypsum Wallboard		114,852			69,712			6,264
	Paperboard		23,610			25,200			16,988
	Concrete and Aggregates		(4,678	)		(5,388	)		(1,097	)
	Other, net		1,368			(1,232	)		356
	Sub-Total		224,638			134,520			69,361
	Corporate General and Administrative		(24,552	)		(23,918	)		(19,617	)
	Other Corporate Charges		—			(10,683	)		(9,117	)
	Earnings Before Interest and Income Taxes		200,086			99,919			40,627
	Loss on Debt Retirement		—			—			(2,094	)
	Interest Expense, net		(18,282	)		(15,823	)		(16,621	)
	Earnings Before Income Taxes	$	181,804		$	84,096		$	21,912
	Cement Operating Earnings -
	Wholly-Owned	$	51,675		$	13,721		$	18,322
	Joint Ventures		37,811			32,507			28,528
		$	89,486		$	46,228		$	46,850
	Capital Expenditures -
	Cement	$	12,226		$	15,583		$	7,753
	Gypsum Wallboard		4,825			2,682			3,357
	Paperboard		3,354			804			919
	Aggregates		34,719			33,829			13,639
	Concrete		4,117			103			321
	Other, net		249			10			110
		$	59,490		$	53,011		$	26,099
	Depreciation, Depletion and Amortization -
	Cement	$	31,829		$	20,658		$	15,373
	Gypsum Wallboard		20,981			21,045			20,903
	Paperboard		8,716			8,824			8,595
	Aggregates		5,119			3,820			3,365
	Concrete		1,793			1,392			1,022
	Corporate and Other		1,583			1,111			866
		$	70,021		$	56,850		$	50,124
		As of March 31,
		2014			2013			2012
	(dollars in thousands)
Identifiable Assets
Cement	$	762,578		$	756,158		$	313,559
Gypsum Wallboard		412,566			425,866			434,967
Paperboard		125,045			129,226			137,483
Aggregates		152,728			108,796			49,009
Concrete		26,835			27,187			12,031
Other, net		31,777			29,000			38,096
	$	1,511,529		$	1,476,233		$	985,145
Segment Breakdown of Goodwill	'
	The segment breakdown of goodwill at March 31, 2014 and 2013 is as follows:
		For the Years Ended March 31,
		2014			2013
		(dollars in thousands)
	Cement	$	8,359		$	8,359
	Gypsum Wallboard		116,618			116,618
	Paperboard		7,538			7,538
		$	132,515		$	132,515

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Schedule of Components of Provision for Income Taxes	'
	The provision for income taxes includes the following components:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Current Provision (Benefit) -
	Federal	$	49,604		$	19,108		$	812
	State		2,211			1,089			180
			51,815			20,197			992
	Deferred Provision (Benefit) -
	Federal		7,691			5,173			1,984
	State		(1,945	)		982			204
			5,746			6,155			2,188
	Provision for Income Taxes	$	57,561		$	26,352		$	3,180
Schedule of Effective Tax Rates Vary from Federal Statutory Rates	'
	The effective tax rates vary from the federal statutory rates due to the following items:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Earnings Before Income Taxes	$	181,804		$	84,096		$	21,912
	Income Taxes at Statutory Rate	$	63,631		$	29,434		$	7,669
	Increases (Decreases) in Tax Resulting from -
	State Income Taxes, net		173			1,346			249
	Statutory Depletion in Excess of Cost		(3,512	)		(3,110	)		(2,619	)
	Domestic Production Activities Deduction		(3,453	)		(1,895	)		36
	Meals and Entertainment Disallowance		503			337			284
	Penalties on Uncertain Tax Positions		213			215			190
	Tax Benefits-ASC 740 Accruals and State Amnesty Programs		—			(42	)		(2,558	)
	Other		6			67			(71	)
	Provision for Income Taxes	$	57,561		$	26,352		$	3,180
	Effective Tax Rate		32	%		31	%		15	%
Schedule of Deferred Income Tax Provision	'
	The deferred income tax provision results from the following temporary differences in the recognition of revenues and expenses for tax and financial reporting purposes:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Excess Tax Depreciation and Amortization	$	6,875		$	7,038		$	4,617
	Bad Debts		(224	)		(73	)		(119	)
	Uniform Capitalization		(1,127	)		(14	)		(1,004	)
	Accrual Changes		(1,075	)		(1,169	)		1,107
	Uncertain Tax Position Accruals		213			173			(2,264	)
	Prepaid Insurance		424			—			—
	Other		660			200			(149	)
		$	5,746		$	6,155		$	2,188
Schedule of Components of Deferred Income Taxes	'
	Components of deferred income taxes are as follows:
		March 31,
		2014			2013
		(dollars in thousands)
	Items Giving Rise to Deferred Tax Liabilities -
	Excess Tax Depreciation and Amortization	$	(144,619	)	$	(142,343	)
	Repair Parts		(4,545	)		(3,827	)
	State Income Taxes		(7,648	)		(8,967	)
	Other		(4,997	)		(4,277	)
	Total Deferred Tax Liabilities	$	(161,809	)	$	(159,414	)
	Items Giving Rise to Deferred Tax Assets -
	Accrual Changes	$	9,946		$	13,352
	Bad Debts		2,122			1,898
	Uniform Capitalization		2,131			1,004
	Other		2,398			4,321
	Total Deferred Tax Assets	$	16,597		$	20,575
Schedule of Income Taxes Classified in Consolidated Balance Sheet	'
	Deferred income taxes are classified in the consolidated balance sheet as follows:
		March 31,
		2014			2013
		(dollars in thousands)
	Prepaid and Other Assets		561			189
	Deferred Income Taxes	$	(145,773	)	$	(139,028	)
Reconciliation of Consolidated Liability for Gross Unrecognized Tax Benefits	'
	Reconciliation of the consolidated liability for gross unrecognized tax benefits, excluding interest, from April 1, 2011 to March 31, 2014, is as follows:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Balance at Beginning of Year	$	24,589		$	25,890		$	28,450
	Increase related to prior tax positions		213			215			534
	Decrease related to prior tax positions		—			(1,516	)		(2,797	)
	Payments		—			—			(297	)
		$	24,802		$	24,589		$	25,890
Summary of Amounts of Interest and Penalties Recognized in Relation to Uncertain Tax Position	'
	The following is a summary of the amounts of interest and penalties recognized in relation to our uncertain tax position:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Accrued interest recognized	$	641		$	409		$	(903	)
	Accrued penalties recognized	$	213		$	173		$	190

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Mar. 31, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Schedule of Minimum Annual Rental Commitments	'
	Minimum annual rental commitments as of March 31, 2014, under noncancellable leases are set forth as follows (dollars in thousands):
	Fiscal Year	Amount
	2015	$	3,155
	2016	$	2,829
	2017	$	2,617
	2018	$	2,004
	2019	$	2,003
	Thereafter	$	4,731

Stock_Option_Plans_Tables

Stock Option Plans (Tables)	12 Months Ended
	Mar. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Weighted-Average Assumptions Used to Value Option Awards	'
	The weighted-average assumptions used in the Black-Scholes model to value the option awards in fiscal 2014 and 2013 are as follows:
		2014			2013
	Dividend Yield		2	%		2	%
	Expected Volatility		44.6	%		44.1	%
	Risk Free Interest Rate		2.04	%		1.7	%
	Expected Life		7.0 years			7.9 years
Stock Option Activity	'
	The following table represents stock option activity for the years presented:
		For the Years Ended March 31,
		2014						2013					2012
		Number			Weighted			Number			Weighted		Number			Weighted
		of			Average			of			Average		of			Average
		Shares			Exercise			Shares			Exercise		Shares			Exercise
					Price						Price					Price
	Outstanding Options at Beginning of Year		3,022,592		$	37.83			3,241,322		$	36.11		3,323,786		$	35.6
	Granted		256,989		$	68			569,679		$	34.64		474,124		$	26.41
	Exercised		(485,582	)	$	29.72			(746,131	)	$	27.64		(383,811	)	$	18.57
	Cancelled		(5,000	)	$	53.22			(42,278	)	$	42.21		(172,777	)	$	38.69
	Outstanding Options at End of Year		2,788,999		$	41.83			3,022,592		$	37.83		3,241,322		$	36.11
	Options Exercisable at End of Year		818,215						986,187					1,567,734
	Weighted Average Fair Value of Options Granted during the Year				$	26.35					$	13.28				$	10.29
Stock Options Outstanding	'
	The following table summarizes information about stock options outstanding at March 31, 2014:
		Options Outstanding									Options Exercisable
	Range of Exercise Prices	Number of			Weighted			Weighted			Number of		Weighted
		Shares			Average			Average			Shares		Average
		Outstanding			Remaining			Exercise			Outstanding		Exercise
					Contractual			Price					Price
					Life
	$23.17 - $30.74		679,191			5.02		$	26.5			559,762	$	26.26
	$33.08 - $40.78		558,000			7.24		$	34.4			206,274	$	35.13
	$47.53 - $87.34		1,551,808			1.86		$	51.21			52,179	$	65.2
			2,788,999			3.7		$	41.83			818,215	$	30.98

Net_Interest_Expense_Tables

Net Interest Expense (Tables)	12 Months Ended
	Mar. 31, 2014
Banking And Thrift Interest [Abstract]	'
Interest Expense, Net	'
	The following components are included in interest expense, net:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Interest Income	$	(5	)	$	(53	)	$	(6	)
	Interest Expense		16,751			14,769			16,969
	Interest Expense (Income) – IRS		641			409			(903	)
	Other Expenses		895			698			561
	Interest Expense, net	$	18,282		$	15,823		$	16,621

Pension_and_Profit_Sharing_Pla1

Pension and Profit Sharing Plans (Tables)	12 Months Ended
	Mar. 31, 2014
Compensation And Retirement Disclosure [Abstract]	'
Schedule of Reconciliation of Obligations and Fair Values of Plan Assets	'
	The following table provides a reconciliation of the obligations and fair values of plan assets for all of our defined benefit plans over the two year period ended March 31, 2014 and a statement of the funded status as of March 31, 2014 and 2013:
		For the Years Ended
		March 31,
		2014			2013
		(dollars in thousands)
	Reconciliation of Benefit Obligations -
	Benefit Obligation at April 1,	$	29,586		$	24,735
	Service Cost - Benefits Earned During the Period		1,129			785
	Interest Cost on Projected Benefit Obligation		1,222			1,222
	Actuarial (Gain) Loss		(1,237	)		3,576
	Benefits Paid		(808	)		(732	)
	Benefit Obligation at March 31,	$	29,892		$	29,586
	Reconciliation of Fair Value of Plan Assets -
	Fair Value of Plan Assets at April 1,	$	18,693		$	17,310
	Actual Return on Plan Assets		1,735			1,598
	Employer Contributions		1,569			517
	Benefits Paid		(808	)		(732	)
	Fair Value of Plans at March 31,		21,189			18,693
	Funded Status -
	Unfunded Status at March 31,	$	(8,703	)	$	(10,893	)
	Amounts Recognized in the Balance Sheet Consist of -
	Accrued Benefit Liability	$	(8,703	)	$	(10,893	)
	Accumulated Other Comprehensive Losses:
	Net Actuarial Loss		8,419			10,812
	Prior Service Cost		15			22
	Accumulated Other Comprehensive Losses	$	8,434		$	10,834
	Tax impact		(2,952	)		(3,792	)
	Accumulated Other Comprehensive Losses, net of tax	$	5,482		$	7,042
Schedule of Accumulated Benefit Obligation in Excess of Plan Assets	'
	Information for pension plans with an accumulated benefit obligation in excess of plan assets:
		March 31,
		2014			2013
		(dollars in thousands)
	Projected Benefit Obligation	$	29,892		$	29,586
	Accumulated Benefit Obligation	$	29,827		$	29,497
	Fair Value of Plan Assets	$	21,189		$	18,693
Components of Net Periodic Cost	'
	Net periodic pension cost for the fiscal years ended March 31, 2014, 2013 and 2012, included the following components:
		For the Years Ended March 31,
		2014			2013			2012
		(dollars in thousands)
	Service Cost - Benefits Earned During the Period	$	1,129		$	785		$	561
	Interest Cost of Projected Benefit Obligation		1,222			1,222			1,104
	Expected Return on Plan Assets		(1,506	)		(1,371	)		(1,293	)
	Recognized Net Actuarial Loss		921			980			242
	Amortization of Prior-Service Cost		11			21			33
	Net Periodic Pension Cost	$	1,777		$	1,637		$	647
Schedule of Expected Benefit Payments	'
	Expected benefit payments over the next five years, and the following five years under the pension plans are expected to be as follows (in thousands):
	Fiscal Years	Total
	2015	$	978
	2016	$	1,065
	2017	$	1,113
	2018	$	1,184
	2019	$	1,280
	2020-2024	$	8,307
Schedule of Assumptions Used in Net Periodic Benefit Cost and Benefit Obligations	'
	The following table sets forth the assumptions used in the actuarial calculations of the present value of net periodic benefit cost and benefit obligations:
		March 31,
		2014			2013			2012
	Net Periodic Benefit Costs -
	Discount Rate		4.2	%		4.56	%		5.61	%
	Expected Return on Plan Assets		8	%		8	%		8	%
	Rate of Compensation Increase		3.5	%		3.5	%		3.5	%
		March 31,
		2014			2013
	Benefit Obligations -
	Discount Rate		4.41	%		4.2	%
	Rate of Compensation Increase		3.5	%		3.5	%
Schedule of Pension Plans Weighted-Average Asset Allocation and Range of Target Allocation	'
	The pension plans’ approximate weighted-average asset allocation at March 31, 2014 and 2013 and the range of target allocation are as follows:
		Range of			Percentage of
		Target			Plan
					Assets at
					March 31,
		Allocation			2014			2013
	Asset Category -
	Equity Securities		40 – 60	%		65	%		60	%
	Debt Securities		35 – 60	%		30	%		30	%
	Other		0 – 5	%		5	%		10	%
	Total					100	%		100	%
Schedule of Fair Values of Defined Benefit Plans	'
	The fair values of our defined benefit plans’ consolidated assets by category as of March 31, 2014 and 2013 were as follows:
		March 31,
		2014			2013
		(dollars in thousands)
	Equity Securities	$	13,973		$	12,034
	Fixed Income Securities		6,526			5,752
	Real Estate Funds		130			287
	Commodity Linked Funds		170			420
	Cash Equivalents		390			200
	Total	$	21,189		$	18,693
Schedule of Fair Values of Defined Benefit Plans Determined Using Fair Value Hierarchy of Inputs	'
	The fair values by category of inputs as of March 31, 2014 were as follows:
	Asset Categories	Quoted Prices in			Significant			Significant			Total
		Active Markets			Other			Unobservable
		for Identical			Observable			Inputs
		Assets			Inputs			(Level 3)
		(Level 1)			(Level 2)
		(dollars in thousands)
	Equity Securities	$	—		$	13,973		$	—		$	13,973
	Fixed Income Securities		—			6,526			—			6,526
	Real Estate Funds		—			130			—			130
	Commodity Linked Funds		—			170			—			170
	Cash Equivalents		390			—			—			390
		$	390		$	20,799		$	—		$	21,189
	The fair values by category of inputs as of March 31, 2013 were as follows:
	Asset Categories	Quoted Prices in			Significant			Significant			Total
		Active Markets			Other			Unobservable
		for Identical			Observable			Inputs
		Assets			Inputs			(Level 3)
		(Level 1)			(Level 2)
		(dollars in thousands)
	Equity Securities	$	—		$	12,034		$	—		$	12,034
	Fixed Income Securities		—			5,752			—			5,752
	Real Estate Funds		—			287			—			287
	Commodity Linked Funds		—			420			—			420
	Cash Equivalents		200			—			—			200
		$	200		$	18,493		$	—		$	18,693

Significant_Accounting_Policie3

Significant Accounting Policies - Additional Information (Detail) (USD $)	0 Months Ended		1 Months Ended		3 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	4-May-11	Jun. 29, 2010	Mar. 31, 2010	Nov. 30, 2007	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'
Ownership percentage	'	'	'	'	50.00%	'	50.00%	'	'
Allowance for doubtful accounts	'	'	'	'	$5.80	$5.10	$5.80	$5.10	'
Notes receivable, total	'	'	'	'	9.3	'	9.3	'	'
Notes receivable, current	'	'	'	'	6.3	'	6.3	'	'
Notes Receivable basis spread on Prime rate	'	'	'	'	'	'	4.30%	'	'
Depreciable assets	'	'	'	'	'	'	67.3	55.1	48.9
Carrying value of plant	'	'	'	'	2.9	'	2.9	'	'
Carrying value of equipment	'	'	'	'	1.6	'	1.6	'	'
Amortization expense of intangibles	'	'	'	'	'	'	1.7	1	0.6
Amortization expense, expected, for fiscal years 2015	'	'	'	'	1.7	'	1.7	'	'
Amortization expense, expected, for fiscal years 2016	'	'	'	'	1.7	'	1.7	'	'
Amortization expense, expected, for fiscal years 2017	'	'	'	'	1.5	'	1.5	'	'
Amortization expense, expected, for fiscal years 2018	'	'	'	'	1	'	1	'	'
Amortization expense, expected, for fiscal years 2019	'	'	'	'	1	'	1	'	'
Stock repurchases approved by Board of Directors	'	'	'	'	31,610,605	'	31,610,605	'	'
Shares remain available for repurchase	'	'	'	'	717,300	'	717,300	'	'
Accumulated other comprehensive loss	'	'	'	'	5.5	'	5.5	'	'
Net of income taxes for accumulated other comprehensive loss	'	'	'	'	'	'	'	3	'
Interest payments	'	'	'	'	'	'	17	14.6	18.8
Income taxes paid	97.9	13.6	18.1	27.6	'	'	41.7	14.8	'
Federal and state income taxes, refund received	'	0.8	'	'	'	'	'	'	8
Maintenance and repair expenses	'	'	'	'	4.5	14	77.4	61.3	37.6
Repurchased senior debt	'	'	'	'	'	'	'	'	88.1
Repurchased senior debt transaction costs	'	'	'	'	'	'	'	'	2.1
Stock options outstanding (in shares)	'	'	'	'	'	'	146,696	1,082,380	2,773,279
Stock options, average exercise price per share	'	'	'	'	'	'	$65.12	$39.65	$42.17
Notes Receivable [Member]	'	'	'	'	'	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'
Allowance for doubtful accounts	'	'	'	'	0.3	0.3	0.3	0.3	'
Revenues And Freight Costs [Member]	'	'	'	'	'	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'	'	'	'	'	'
Freight costs as cost of goods sold	'	'	'	'	'	'	$113.10	$83.20	$66

Schedule_of_Inventories_Detail

Schedule of Inventories (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Inventory [Line Items]	'	'
Inventories	$187,096	$156,380
Raw Materials and Material-in-Progress [Member]	'	'
Inventory [Line Items]	'	'
Inventories	82,319	60,026
Finished Cement [Member]	'	'
Inventory [Line Items]	'	'
Inventories	19,173	18,077
Gypsum Wallboard [Member]	'	'
Inventory [Line Items]	'	'
Inventories	7,144	6,855
Aggregates [Member]	'	'
Inventory [Line Items]	'	'
Inventories	12,090	12,830
Paperboard [Member]	'	'
Inventory [Line Items]	'	'
Inventories	4,102	2,867
Repair Parts and Supplies [Member]	'	'
Inventory [Line Items]	'	'
Inventories	56,119	49,361
Fuel and Coal [Member]	'	'
Inventory [Line Items]	'	'
Inventories	$6,149	$6,364

Schedule_of_Property_Plant_And

Schedule of Property, Plant And Equipment Estimated Lives (Detail)	12 Months Ended
	Mar. 31, 2014
Plants [Member] | Minimum [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated lives of assets - (years)	'20 years
Plants [Member] | Maximum [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated lives of assets - (years)	'30 years
Buildings [Member] | Minimum [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated lives of assets - (years)	'20 years
Buildings [Member] | Maximum [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated lives of assets - (years)	'40 years
Machinery and Equipment [Member] | Minimum [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated lives of assets - (years)	'3 years
Machinery and Equipment [Member] | Maximum [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated lives of assets - (years)	'25 years

Schedule_of_Goodwill_and_Intan

Schedule of Goodwill and Intangible Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Finite-Lived Intangible Assets [Line Items]	'	'
Cost	$168,315	$168,315
Accumulated Amortization	-7,625	-5,915
Total intangible assets and goodwill, Net	160,690	162,400
Customer contracts and relationships [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Amortization Period (years)	'15 years	'15 years
Cost	6,060	6,060
Accumulated Amortization	-1,580	-1,176
Total intangible assets and goodwill, Net	4,480	4,884
Sales contracts [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Amortization Period (years)	'4 years	'4 years
Cost	2,500	2,500
Accumulated Amortization	-833	-208
Total intangible assets and goodwill, Net	1,667	2,292
Permits [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Amortization Period (years)	'40 years	'40 years
Cost	27,240	27,240
Accumulated Amortization	-5,212	-4,531
Total intangible assets and goodwill, Net	22,028	22,709
Goodwill [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Cost	132,515	132,515
Accumulated Amortization	'	'
Total intangible assets and goodwill, Net	$132,515	$132,515

Schedule_of_Total_Selling_Gene

Schedule of Total Selling, General and Administrative Expenses (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Accounting Policies [Abstract]	'	'	'
Operating Units Selling, G&A	$50,175	$39,133	$27,695
Corporate G&A	24,552	23,918	19,617
Total selling, general and administrative expenses	$74,727	$63,051	$47,312

Schedule_of_Earnings_Per_Share

Schedule of Earnings Per Share (Detail)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'
Weighted-Average Shares of Common Stock Outstanding	49,090,750	46,622,646	44,224,924
Assumed Exercise of Outstanding Dilutive Options	1,574,491	1,984,563	800,748
Less Shares Repurchased from Proceeds of Assumed Exercised Options	-1,032,359	-1,568,604	-652,046
Restricted Stock Units	306,283	301,845	142,355
Weighted-Average Common Stock and Dilutive Securities Outstanding	49,939,165	47,340,450	44,515,981

Acquisition_Additional_Informa

Acquisition - Additional Information (Detail) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Nov. 30, 2012
Business Acquisition [Line Items]	'	'	'
Purchase price	'	'	$450,699,000
Final Working Capital Adjustment	'	'	2,734,000
Direct acquisition cost	$6,100,000	$6,100,000	'
Asset Purchase Agreement [Member] | Cement [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Number of business assets acquired	'	'	2
Asset Purchase Agreement [Member] | Aggregates Quarries [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Number of business assets acquired	'	'	2
Asset Purchase Agreement [Member] | Ready-mix Plants [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Number of business assets acquired	'	'	8

Components_of_Purchase_Price_A

Components of Purchase Price Allocation (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Nov. 30, 2012
In Thousands, unless otherwise specified
Business Combinations [Abstract]	'	'	'
Cash and cash equivalents	'	'	'
Accounts Receivable	'	'	23,432
Inventories	'	'	20,361
Prepaid and Other Assets	'	'	3,511
Property and Equipment	'	'	407,260
Intangible Assets	12,500	'	12,500
Accounts Payable	'	'	-9,070
Accrued Liabilities	'	'	-3,501
Other Long-term Liabilities	'	'	-1,060
Total Net Assets	'	'	453,433
Goodwill	132,515	132,515	'
Initial Purchase Price	'	'	453,433
Final Working Capital Adjustment	'	'	-2,734
Final Purchase Price	'	'	$450,699

Summary_of_Fair_Value_Estimate

Summary of Fair Value Estimates of Identifiable Intangible Assets and Weighted-Average Useful Lives (Detail) (USD $)	Mar. 31, 2014	Nov. 30, 2012	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified			Customer Relationships [Member]	Sales contracts [Member]	Permits [Member]
Business Acquisition [Line Items]	'	'	'	'	'
Weighted Average Life	'	'	'15 years	'4 years	'40 years
Fair Value	$12,500	$12,500	$4,760	$2,500	$5,240

Net_Sales_and_Operating_Income

Net Sales and Operating Income of Acquired Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'
Net Sales	'	$792,979	$660,401
Operating income (loss)	224,638	134,520	69,361
Recently Acquired Assets [Member]	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'
Net Sales	158,764	28,892	'
Operating income (loss)	$25,249	($12,531)	'

Unaudited_Pro_Forma_Results_De

Unaudited Pro Forma Results (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Business Combinations [Abstract]	'	'
Revenues	$792,979	$660,401
Net Income	$71,361	$7,460
Earnings per share - basis	$1.48	$0.16
Earnings per share - diluted	$1.45	$0.16
Weighted Average Shares Outstanding:	'	'
Basic	48,352,346	47,647,924
Diluted	49,070,150	47,965,981

Recovered_Sheet1

Schedule of Property, Plant and Equipment (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Gross	$1,660,975	$1,599,992
Accumulated Depreciation	-676,924	-614,268
Property, Plant and Equipment, Net	984,051	985,724
Land And Quarries [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Gross	171,987	154,710
Plants [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Gross	1,357,594	1,324,489
Buildings Machinery And Equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Gross	111,263	110,138
Construction in Progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Gross	$20,131	$10,655

Property_Plant_and_Equipment_A

Property, Plant and Equipment - Additional Information (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Mining and related assets	$984,051	$985,724
Mining Properties and Mineral Rights [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Mining and related assets	$124,900	$83,900

Schedule_of_Accrued_Expenses_D

Schedule of Accrued Expenses (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Accounts Payable and Accrued Liabilities, Current [Abstract]	'	'
Payroll and Incentive Compensation	$12,855	$11,827
Benefits	10,158	10,349
Interest	4,813	4,813
Property Taxes	2,801	3,235
Power and Fuel	2,132	3,146
Legal	1,831	792
Sales and Use Tax	658	591
Acquisition Related Expenses	'	2,023
Other	6,272	4,573
Accrued expenses, total	$41,520	$41,349

LongTerm_Debt_Detail

Long-Term Debt (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Total	$381,259	$489,259
Less: Current Portion of Long-term Debt	-9,500	'
Long-term Debt	371,759	489,259
Bank Credit Facility [Member]	'	'
Debt Instrument [Line Items]	'	'
Total	189,000	297,000
Senior Notes [Member]	'	'
Debt Instrument [Line Items]	'	'
Total	$192,259	$192,259

Indebtedness_Additional_Inform

Indebtedness - Additional Information (Detail) (USD $)

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

78 Months Ended

0 Months Ended

12 Months Ended

100 Months Ended

1 Months Ended

0 Months Ended

0 Months Ended

1 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Dec. 31, 1998

Dec. 16, 2011

Mar. 31, 2014

Mar. 31, 2014

Oct. 02, 2007

Dec. 16, 2011

Mar. 31, 2014

Mar. 31, 2014

Nov. 15, 2005

Nov. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Sep. 26, 2012

Dec. 16, 2010

Sep. 26, 2012

Dec. 16, 2010

Sep. 26, 2012

Dec. 16, 2010

Sep. 26, 2012

Sep. 26, 2012

Sep. 26, 2012

Sep. 26, 2012

Sep. 26, 2012

Sep. 26, 2012

Sep. 26, 2012

Mar. 31, 2014

Aug. 31, 2011

Industrial Revenue Bonds [Member]

Industrial Revenue Bonds [Member]

2007 Note Purchase Agreement [Member]

2007 Note Purchase Agreement [Member]

2007 Note Purchase Agreement [Member]

2007 Note Purchase Agreement [Member]

2005 Note Purchase Agreement [Member]

2005 Note Purchase Agreement [Member]

2005 Note Purchase Agreement [Member]

2005 Note Purchase Agreement [Member]

2005 Note Purchase Agreement [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Bank Credit Facility [Member]

Bank Credit Facility [Member]

Bank Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

Credit Facility [Member]

New Credit Facility [Member]

New Credit Facility [Member]

Shelf Agreement [Member]

Loan

Loan

Series 2005A Tranche A [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Sub Limit Swing Line Loans [Member]

Sub Limit Swing Line Loans [Member]

Minimum [Member]

Maximum [Member]

Federal Funds Rate [Member]

Federal Funds Rate [Member]

LIBOR [Member]

LIBOR [Member]

Letter Of Credit [Member]

Letter Of Credit [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase of aggregate principal amount

'

'

$88,100,000

'

'

$59,100,000

'

'

'

$29,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase amount

'

'

'

'

'

60,200,000

'

'

'

29,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase of accrued interest

'

'

'

'

'

300,000

'

'

'

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.81%

5.81%

5.78%

1.90%

2.00%

2.60%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate of debt instrument

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.81%

5.81%

'

1.50%

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior notes, sale

'

'

'

'

'

'

'

'

200,000,000

'

'

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of tranches

'

'

'

'

'

'

'

'

4

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior notes, repurchased amount

'

1,751,000

'

'

'

'

'

122,000,000

'

'

'

81,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Retirement of senior note

'

'

'

'

'

'

'

'

'

'

'

'

'

4,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior notes, payment terms

'

'

'

'

'

'

'Interest for each tranche of Notes is payable semi-annually on April 2 and October 2 of each year until all principal is paid for the respective tranche.

'

'

'

'Interest for each tranche of Notes is payable semi-annually on May 15 and November 15 of each year until all principal is paid for the respective tranche.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior notes, permitted minimum aggregate principal amount prepayment without penalty

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of face value to be paid if notes are prepaid

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior notes, calculation of make-whole amount, description

'Discounting the remaining scheduled payments of interest and principal of the Senior Notes being prepaid at a discount rate equal to the sum of 50 basis points

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Discount on senior notes principal and interest

0.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility, principal balance

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400,000,000

300,000,000

25,000,000

15,000,000

'

'

'

'

'

'

'

'

'

Credit facility, maturity date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16-Dec-15

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility, interest rate description

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'At the option of the Company, outstanding principal amounts on the Credit Facility bear interest at a variable rate equal to (i) LIBOR, plus an agreed margin (ranging from 100 to 225 basis points), which is to be established quarterly based upon the Companybs ratio of consolidated EBITDA, defined as earnings before interest, taxes, depreciation and amortization, to the Companybs consolidated indebtedness (the bLeverage Ratiob), or (ii) an alternative base rate which is the higher of (a) the prime rate or (b) the federal funds rate plus 1b 2%, per annum plus an agreed margin (ranging from 0 to 125 basis points).

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Variable margin

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.00%

1.25%

1.00%

2.25%

'

'

'

Federal funds rate plus

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.50%

'

'

'

'

'

Consolidated funded indebtedness ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3.51.0 or less and an interest coverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest coverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted payments maximum amount allowed for cash dividend

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unused line of credit commitment fee based on leverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.10%

0.35%

'

'

'

'

'

'

'

Borrowings outstanding under Credit Facility

189,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bank credit facility, borrowings available

203,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted payments maximum consolidated funded indebtedness ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Letter of credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50,000,000

'

Bank credit facility, one-time fee

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.13%

'

'

Letters of credit outstanding, amount

7,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,400,000

'

Proceeds from issuance of tax-exempt and taxable industrial revenue bonds

'

'

'

'

150,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Industrial revenue bonds amount placed in escrow account

'

'

'

47,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Industrial revenue bonds outstanding

381,259,000

489,259,000

'

103,000,000

'

'

'

'

'

'

'

'

'

'

192,259,000

192,259,000

'

189,000,000

297,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Remaining amount of industrial revenue bonds transferred in acquisition

'

'

'

103,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior unsecured notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$75,000,000

Repayment term, years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'Two

Schedule_of_Maturities_of_Long

Schedule of Maturities of Long-Term Debt (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
2015	$9,500	'
2016	246,045	'
2017	8,000	'
2018	81,214	'
2019	'	'
Thereafter	36,500	'
Total	$381,259	$489,259

Amount_Outstanding_of_Tranches

Amount Outstanding of Tranches - Two Thousand Five Note Purchase Agreement (Detail) (2005 Note Purchase Agreement [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Series 2005A Tranche B [Member]	'
Debt Instrument [Line Items]	'
Principal	$57
Maturity Date	15-Nov-15
Interest Rate	5.38%
Series 2005A Tranche C [Member]	'
Debt Instrument [Line Items]	'
Principal	$57.20
Maturity Date	15-Nov-17
Interest Rate	5.48%

Amount_Outstanding_of_Tranches1

Amount Outstanding of Tranches - Two Thousand Seven Note Purchase Agreement (Detail) (2007 Note Purchase Agreement [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Series 2007A Tranche A [Member]	'
Debt Instrument [Line Items]	'
Principal	$9.50
Maturity Date	2-Oct-14
Interest Rate	6.08%
Series 2007A Tranche B [Member]	'
Debt Instrument [Line Items]	'
Principal	8
Maturity Date	2-Oct-16
Interest Rate	6.27%
Series 2007A Tranche C [Member]	'
Debt Instrument [Line Items]	'
Principal	24
Maturity Date	2-Oct-17
Interest Rate	6.36%
Series 2007A Tranche D [Member]	'
Debt Instrument [Line Items]	'
Principal	$36.50
Maturity Date	2-Oct-19
Interest Rate	6.48%

Fair_Value_of_Senior_Notes_Det

Fair Value of Senior Notes (Detail) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Series 2005A Tranche B [Member]	'
Fair Value of Financial Instruments [Line Items]	'
Fair Value of Senior Notes	$59,526
Series 2005A Tranche C [Member]	'
Fair Value of Financial Instruments [Line Items]	'
Fair Value of Senior Notes	60,933
Series 2007A Tranche A [Member]	'
Fair Value of Financial Instruments [Line Items]	'
Fair Value of Senior Notes	9,676
Series 2007A Tranche B [Member]	'
Fair Value of Financial Instruments [Line Items]	'
Fair Value of Senior Notes	8,624
Series 2007A Tranche C [Member]	'
Fair Value of Financial Instruments [Line Items]	'
Fair Value of Senior Notes	26,208
Series 2007A Tranche D [Member]	'
Fair Value of Financial Instruments [Line Items]	'
Fair Value of Senior Notes	$40,187

Business_Segments_Additional_I

Business Segments - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2012
	Segment
Segment Reporting Information [Line Items]	'	'
Business segments	4	'
Cement plant locations	6	'
Cement distribution terminals	16	'
Gypsum wallboard plants	5	'
Readymix concrete batch plant	17	'
Aggregates processing plant	4	'
Proportionate consolidation of share of Joint Venture's revenues and operating earnings	50.00%	'
Amount provided for joint venture capital needs	'	$12
Cement [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Number of Joint Venture	1	'

Financial_Information_Related_

Financial Information Related to Operations by Segment (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	$898,396	$642,562	$495,023
Operating Earnings	'	'	'	'	'	'	'	'	224,638	134,520	69,361
Corporate General and Administrative	'	'	'	'	'	'	'	'	-24,552	-23,918	-19,617
Capital Expenditures	'	'	'	'	'	'	'	'	59,490	53,011	26,099
Other Corporate Charges	'	'	'	'	'	'	'	'	'	-10,683	-9,117
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	70,021	56,850	50,124
Earnings Before Interest and Income Taxes	'	'	'	'	'	'	'	'	200,086	99,919	40,627
Identifiable Assets	1,511,529	'	'	'	1,476,233	'	'	'	1,511,529	1,476,233	985,145
Loss on Debt Retirement	'	'	'	'	'	'	'	'	'	'	-2,094
Interest Expense, net	'	'	'	'	'	'	'	'	-18,282	-15,823	-16,621
Earnings Before Income Taxes	29,767	48,833	58,688	44,516	10,756	27,301	26,125	19,914	181,804	84,096	21,912
Joint Venture [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	111,393	96,322	86,140
Cement [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Cement Sales Volume	'	'	'	'	'	'	'	'	4,593,000	3,303,000	2,723,000
Operating Earnings	'	'	'	'	'	'	'	'	89,486	46,228	46,850
Identifiable Assets	762,578	'	'	'	756,158	'	'	'	762,578	756,158	313,559
Cement [Member] | Joint Venture [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Cement Sales Volume	'	'	'	'	'	'	'	'	1,013,000	913,000	866,000
Operating Earnings	'	'	'	'	'	'	'	'	37,811	32,507	28,528
Cement [Member] | Wholly-Owned [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Cement Sales Volume	'	'	'	'	'	'	'	'	3,580,000	2,390,000	1,857,000
Operating Earnings	'	'	'	'	'	'	'	'	51,675	13,721	18,322
Gypsum Wallboard [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Identifiable Assets	412,566	'	'	'	425,866	'	'	'	412,566	425,866	434,967
Paperboard [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Identifiable Assets	125,045	'	'	'	129,226	'	'	'	125,045	129,226	137,483
Other Segments [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Identifiable Assets	31,777	'	'	'	29,000	'	'	'	31,777	29,000	38,096
Aggregates [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Identifiable Assets	152,728	'	'	'	108,796	'	'	'	152,728	108,796	49,009
Concrete [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Identifiable Assets	26,835	'	'	'	27,187	'	'	'	26,835	27,187	12,031
Operating Segments [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	1,071,883	788,871	625,920
Operating Segments [Member] | Cement [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	438,224	304,125	243,978
Operating Earnings	'	'	'	'	'	'	'	'	89,486	46,228	46,850
Capital Expenditures	'	'	'	'	'	'	'	'	12,226	15,583	7,753
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	31,829	20,658	15,373
Operating Segments [Member] | Gypsum Wallboard [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	387,016	306,529	217,633
Operating Earnings	'	'	'	'	'	'	'	'	114,852	69,712	6,264
Capital Expenditures	'	'	'	'	'	'	'	'	4,825	2,682	3,357
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	20,981	21,045	20,903
Operating Segments [Member] | Paperboard [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	130,178	121,930	118,794
Operating Earnings	'	'	'	'	'	'	'	'	23,610	25,200	16,988
Capital Expenditures	'	'	'	'	'	'	'	'	3,354	804	919
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	8,716	8,824	8,595
Operating Segments [Member] | Concrete and Aggregates [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	116,465	56,287	45,515
Operating Earnings	'	'	'	'	'	'	'	'	-4,678	-5,388	-1,097
Operating Segments [Member] | Aggregates [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Capital Expenditures	'	'	'	'	'	'	'	'	34,719	33,829	13,639
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	5,119	3,820	3,365
Operating Segments [Member] | Concrete [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Capital Expenditures	'	'	'	'	'	'	'	'	4,117	103	321
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	1,793	1,392	1,022
Operating Segments [Member] | Corporate and Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Depreciation, Depletion and Amortization	'	'	'	'	'	'	'	'	1,583	1,111	866
Intersegment Eliminations [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	62,094	49,987	44,757
Intersegment Eliminations [Member] | Cement [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	8,952	2,850	3,605
Intersegment Eliminations [Member] | Paperboard [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	52,119	46,393	40,485
Intersegment Eliminations [Member] | Concrete and Aggregates [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net Revenues	'	'	'	'	'	'	'	'	1,023	744	667
Segment Reconciling Items [Member] | Other Segments [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Operating Earnings	'	'	'	'	'	'	'	'	1,368	-1,232	356
Corporate, Non-Segment [Member] | Other Segments [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Capital Expenditures	'	'	'	'	'	'	'	'	$249	$10	$110

Segment_Breakdown_of_Goodwill_

Segment Breakdown of Goodwill (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Nov. 30, 2012
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]	'	'	'
Goodwill	$132,515	$132,515	'
Operating Segments [Member] | Cement [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Goodwill	8,359	8,359	'
Operating Segments [Member] | Gypsum Wallboard [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Goodwill	116,618	116,618	'
Operating Segments [Member] | Paperboard [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Goodwill	$7,538	$7,538	'

Schedule_of_Components_of_Prov

Schedule of Components of Provision for Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'
Current Provision (Benefit) - Federal	$49,604	$19,108	$812
Current Provision (Benefit) - State	2,211	1,089	180
Current Provision (Benefit) - Total	51,815	20,197	992
Deferred Provision (Benefit) - Federal	7,691	5,173	1,984
Deferred Provision (Benefit) - State	-1,945	982	204
Deferred Provision (Benefit) - Total	5,746	6,155	2,188
Provision for Income Taxes	$57,561	$26,352	$3,180

Schedule_of_Effective_Tax_Rate

Schedule of Effective Tax Rates Vary from Federal Statutory Rates (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Earnings Before Income Taxes	$29,767	$48,833	$58,688	$44,516	$10,756	$27,301	$26,125	$19,914	$181,804	$84,096	$21,912
Income Taxes at Statutory Rate	'	'	'	'	'	'	'	'	63,631	29,434	7,669
Increases (Decreases) in Tax Resulting from - State Income Taxes, net	'	'	'	'	'	'	'	'	173	1,346	249
Increases (Decreases) in Tax Resulting from - Statutory Depletion in Excess of Cost	'	'	'	'	'	'	'	'	-3,512	-3,110	-2,619
Increases (Decreases) in Tax Resulting from - Domestic Production Activities Deduction	'	'	'	'	'	'	'	'	-3,453	-1,895	36
Increases (Decreases) in Tax Resulting from - Meals and Entertainment Disallowance	'	'	'	'	'	'	'	'	503	337	284
Increases (Decreases) in Tax Resulting from - Penalties on Uncertain Tax Positions	'	'	'	'	'	'	'	'	213	215	190
Increases (Decreases) in Tax Resulting from - Tax Benefits-ASC 740 Accruals and State Amnesty Programs	'	'	'	'	'	'	'	'	'	-42	-2,558
Increases (Decreases) in Tax Resulting from - Other	'	'	'	'	'	'	'	'	6	67	-71
Provision for Income Taxes	'	'	'	'	'	'	'	'	$57,561	$26,352	$3,180
Effective Tax Rate	'	'	'	'	'	'	'	'	32.00%	31.00%	15.00%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'	'
Tax benefit recognized	$57,561,000	$26,352,000	$3,180,000	'
Accrued interest on uncertain tax position	4,400,000	3,800,000	'	'
Accrued penalties	3,200,000	3,000,000	'	'
Uncertain tax position	24,802,000	24,589,000	25,890,000	28,450,000
Deduction on unrecognized tax benefits	14,900,000	'	'	'
Income tax refund	106,600,000	'	'	'
Reduction of other long-term liabilities	$29,200,000	'	'	'

Schedule_of_Deferred_Income_Ta

Schedule of Deferred Income Tax Provision (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	$5,746	$6,155	$2,188
Excess Tax Depreciation and Amortization [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	6,875	7,038	4,617
Bad Debts [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	-224	-73	-119
Uniform Capitalization [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	-1,127	-14	-1,004
Accrual Changes [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	-1,075	-1,169	1,107
Uncertain Tax Position Accruals [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	213	173	-2,264
Prepaid Insurance [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	424	'	'
Other [Member]	'	'	'
Deferred Income (Benefit) Taxes [Line Items]	'	'	'
Deferred Income Tax Provision	$660	$200	($149)

Schedule_of_Components_of_Defe

Schedule of Components of Deferred Income Taxes (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Items Giving Rise to Deferred Tax Liabilities - Excess Tax Depreciation and Amortization	($144,619)	($142,343)
Items Giving Rise to Deferred Tax Liabilities - Repair Parts	-4,545	-3,827
Items Giving Rise to Deferred Tax Liabilities - State Income Taxes	-7,648	-8,967
Items Giving Rise to Deferred Tax Liabilities - Other	-4,997	-4,277
Items Giving Rise to Deferred Tax Liabilities - Total Deferred Tax Liabilities	-161,809	-159,414
Items Giving Rise to Deferred Tax Assets - Accrual Changes	9,946	13,352
Items Giving Rise to Deferred Tax Assets - Bad Debts	2,122	1,898
Items Giving Rise to Deferred Tax Assets - Uniform Capitalization	2,131	1,004
Items Giving Rise to Deferred Tax Assets - Other	2,398	4,321
Items Giving Rise to Deferred Tax Assets - Total Deferred Tax Assets	$16,597	$20,575

Schedule_of_Income_Taxes_Class

Schedule of Income Taxes Classified in Consolidated Balance Sheet (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Prepaid and Other Assets	$561	$189
Deferred Income Taxes	($145,773)	($139,028)

Reconciliation_of_Consolidated

Reconciliation of Consolidated Liability for Gross Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'
Balance at Beginning of Year	$24,589	$25,890	$28,450
Increase related to prior tax positions	213	215	534
Decrease related to prior tax positions	'	-1,516	-2,797
Payments	'	'	-297
Balance at End of Year	$24,802	$24,589	$25,890

Summary_of_Amounts_of_Interest

Summary of Amounts of Interest and Penalties Recognized in Relation to Uncertain Tax Position (Detail) (USD $)	0 Months Ended	1 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Jun. 29, 2010	Mar. 31, 2010	Nov. 30, 2007	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'	'	'	'
Accrued interest recognized	$7,100	$7,500	$7,500	$641	$409	($903)
Accrued penalties recognized	$2,900	$3,700	$5,700	$213	$173	$190

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended		1 Months Ended		12 Months Ended
	4-May-11	Jun. 29, 2010	Mar. 31, 2010	Nov. 30, 2007	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Jan. 19, 2012
					Agreement
					GeneratingPlant
Commitments And Contingencies [Line Items]	'	'	'	'	'	'	'	'
Contingent liabilities under outstanding letters of credit	'	'	'	'	$7,400,000	'	'	'
Contingently liable for performance, current	'	'	'	'	16,000,000	'	'	'
Taxes And Penalties Including Interest deposited with IRS	'	23,600,000	29,300,000	45,800,000	'	'	'	'
Federal income tax	97,900,000	13,600,000	18,100,000	27,600,000	41,700,000	14,800,000	'	'
Penalties	'	2,900,000	3,700,000	5,700,000	213,000	173,000	190,000	'
Interest on income tax	'	7,100,000	7,500,000	7,500,000	641,000	409,000	-903,000	'
Federal and state income taxes, refund received	'	800,000	'	'	'	'	8,000,000	'
Number of agreements	'	'	'	'	2	'	'	'
Legal award to mining companies	'	'	'	'	'	'	'	6,900,000
Legal award to other parties	'	'	'	'	'	'	'	1,200,000
Sale percentage of gypsum-grade recycled paperboard	'	'	'	'	90.00%	'	'	'
Number of plants	'	'	'	'	3	'	'	'
Percentage of expected natural gas usage	'	'	'	'	25.00%	'	'	'
Operating leases Rental expense	'	'	'	'	$3,200,000	$1,600,000	$1,700,000	'
Minimum [Member]	'	'	'	'	'	'	'	'
Commitments And Contingencies [Line Items]	'	'	'	'	'	'	'	'
Sale percentage of gypsum-grade recycled paperboard	'	'	'	'	15.00%	'	'	'
Maximum [Member]	'	'	'	'	'	'	'	'
Commitments And Contingencies [Line Items]	'	'	'	'	'	'	'	'
Sale percentage of gypsum-grade recycled paperboard	'	'	'	'	20.00%	'	'	'

Schedule_of_Minimum_Annual_Ren

Schedule of Minimum Annual Rental Commitments (Detail) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
2015	$3,155
2016	2,829
2017	2,617
2018	2,004
2019	2,003
Thereafter	$4,731

Stock_Option_Plans_Additional_

Stock Option Plans - Additional Information (Detail) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Aug. 07, 2013

Aug. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Aug. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Aug. 07, 2013

Aug. 31, 2013

Mar. 31, 2012

Aug. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Stock Awards [Member]

Fiscal 2014 Employee Stock Option Grant [Member]

Fiscal 2014 Employee Stock Option Grant [Member]

Fiscal 2014 Board of Directors Grant [Member]

Stock Options [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Board of Directors [Member]

Minimum [Member]

Maximum [Member]

Share Based Employee Compensation [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares available for future grant

3,981,878

'

'

3,000,000

'

'

'

'

'

'

'

1,500,000

'

'

'

'

'

'

'

Number of shares granted

256,989

569,679

474,124

'

'

'

'

'

'

'

'

'

206,914

'

30,075

'

'

'

'

Share-based compensation vesting period

'

'

'

'

'

'5 years

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

Share-based compensation award expiration term

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'10 years

'

'

'

'

Stock option expense

$5.30

$4

$1.40

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock option grants expense

'

'

'

'

'

'

'

'

'

'

'

'

'

1.3

'

'

'

'

'

Unrecognized compensation cost

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.2

0.1

'

'

Weighted-average period of recognition of unrecognized compensation cost

'

'

'

'

'

'3 years 2 months 12 days

'

'

'

'

'

'

'

'

'

'2 years

'2 years

'

'

Aggregate intrinsic value for outstanding options

130.6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate intrinsic value of exercisable options

47.2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total intrinsic value of options exercised

22.1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock or unit expense

'

'

'

'

'

4.8

3.4

2.6

'

'

'

'

'

'

'

'

0

1.6

1.5

Unvested RSUs (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,000

'

'

Number of shares granted

'

'

'

'

93,186

'

'

'

5,761

'

'

'

'

'

'

'

'

'

'

Percentage of average return on invested capital

'

'

'

'

'

'

'

'

'

15.00%

'

'

'

'

'

'

'

'

'

Period of average return on invested capital exceeded target

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation vesting date

'

'

'

'

'

'

'

'

'

31-Mar-15

31-Mar-18

'

'

'

'

'

'

'

'

Remaining restrictions of unearned compensation cost

'

'

'

'

'

560,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation cost

'

'

'

'

'

$15

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum number of shares available for grant

1,538,021

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

WeightedAverage_Assumptions_Us

Weighted-Average Assumptions Used to Value Option Awards (Detail) (Fiscal 2014 Board of Directors Grant [Member])	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Fiscal 2014 Board of Directors Grant [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Dividend Yield	2.00%	2.00%
Expected Volatility	44.60%	44.10%
Risk Free Interest Rate	2.04%	1.70%
Expected Life	'7 years	'7 years 10 months 24 days

Stock_Option_Activity_Detail

Stock Option Activity (Detail) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'
Number of Shares, Outstanding Options at Beginning of Year	3,022,592	3,241,322	3,323,786
Number of Shares, Granted	256,989	569,679	474,124
Number of Shares, Exercised	-485,582	-746,131	-383,811
Number of Shares, Cancelled	-5,000	-42,278	-172,777
Number of Shares, Outstanding Options at End of Year	2,788,999	3,022,592	3,241,322
Number of Shares, Options Exercisable at End of Year	818,215	986,187	1,567,734
Weighted-Average Exercise Price, Outstanding Options at Beginning of year	$37.83	$36.11	$35.60
Weighted-Average Exercise Price, Granted	$68	$34.64	$26.41
Weighted-Average Exercise Price, Exercised	$29.72	$27.64	$18.57
Weighted-Average Exercise Price, Cancelled	$53.22	$42.21	$38.69
Weighted-Average Exercise Price, Outstanding Options at End of Year	$41.83	$37.83	$36.11
Weighted-Average Exercise Price, Options Exercisable at End of Year	'	'	'
Weighted-Average Exercise Price, Weighted-Average Fair Value of Options Granted during the Year	$26.35	$13.28	$10.29

Stock_Options_Outstanding_Deta

Stock Options Outstanding (Detail) (USD $)	12 Months Ended
	Mar. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Options Outstanding, Number of Shares Outstanding	2,788,999
Options Outstanding, Weighted-Average Remaining Contractual Life	'3 years 8 months 12 days
Options Outstanding, Weighted-Average Exercise Price	$41.83
Options Exercisable, Number of Shares Outstanding	818,215
Options Exercisable, Weighted-Average Exercise Price	$30.98
$23.17 - $30.74 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Range	$23.17
Range of Exercise Prices, Upper Range	$30.74
Options Outstanding, Number of Shares Outstanding	679,191
Options Outstanding, Weighted-Average Remaining Contractual Life	'5 years 7 days
Options Outstanding, Weighted-Average Exercise Price	$26.50
Options Exercisable, Number of Shares Outstanding	559,762
Options Exercisable, Weighted-Average Exercise Price	$26.26
$33.08 - $40.78 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Range	$33.08
Range of Exercise Prices, Upper Range	$40.78
Options Outstanding, Number of Shares Outstanding	558,000
Options Outstanding, Weighted-Average Remaining Contractual Life	'7 years 2 months 27 days
Options Outstanding, Weighted-Average Exercise Price	$34.40
Options Exercisable, Number of Shares Outstanding	206,274
Options Exercisable, Weighted-Average Exercise Price	$35.13
$47.53 - $87.34 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Range	$47.53
Range of Exercise Prices, Upper Range	$87.34
Options Outstanding, Number of Shares Outstanding	1,551,808
Options Outstanding, Weighted-Average Remaining Contractual Life	'1 year 10 months 10 days
Options Outstanding, Weighted-Average Exercise Price	$51.21
Options Exercisable, Number of Shares Outstanding	52,179
Options Exercisable, Weighted-Average Exercise Price	$65.20

Interest_Expense_Net_Detail

Interest Expense, Net (Detail) (USD $)	0 Months Ended	1 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Jun. 29, 2010	Mar. 31, 2010	Nov. 30, 2007	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Interest Income (Expense), Net [Abstract]	'	'	'	'	'	'
Interest Income	'	'	'	($5)	($53)	($6)
Interest Expense	'	'	'	16,751	14,769	16,969
Interest Expense (Income) - IRS	7,100	7,500	7,500	641	409	-903
Other Expenses	'	'	'	895	698	561
Interest Expense, net	'	'	'	$18,282	$15,823	$16,621

Schedule_of_Reconciliation_of_

Schedule of Reconciliation of Obligations and Fair Values of Plan Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Compensation And Retirement Disclosure [Abstract]	'	'	'
Benefit Obligation at April 1,	$29,586	$24,735	'
Service Cost - Benefits Earned During the Period	1,129	785	561
Interest Cost on Projected Benefit Obligation	1,222	1,222	1,104
Actuarial (Gain) Loss	-1,237	3,576	'
Benefits Paid	-808	-732	'
Benefit Obligation at March 31,	29,892	29,586	24,735
Fair Value of Plan Assets at April 1,	18,693	17,310	'
Actual Return on Plan Assets	1,735	1,598	'
Employer Contributions	1,569	517	'
Benefits Paid	-808	-732	'
Fair Value of Plans at March 31,	21,189	18,693	17,310
Unfunded Status at March 31,	-8,703	-10,893	'
Accrued Benefit Liability	-8,703	-10,893	'
Accumulated Other Comprehensive Losses - Net Actuarial Loss	8,419	10,812	'
Accumulated Other Comprehensive Losses - Prior Service Cost	15	22	'
Accumulated Other Comprehensive Losses	8,434	10,834	'
Tax impact	-2,952	-3,792	'
Accumulated Other Comprehensive Losses, net of tax	$5,482	$7,042	'

Schedule_of_Accumulated_Benefi

Schedule of Accumulated Benefit Obligation in Excess of Plan Assets (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
In Thousands, unless otherwise specified
Compensation And Retirement Disclosure [Abstract]	'	'	'
Projected Benefit Obligation	$29,892	$29,586	$24,735
Accumulated Benefit Obligation	29,827	29,497	'
Fair Value of Plan Assets	$21,189	$18,693	$17,310

Components_of_Net_Periodic_Cos

Components of Net Periodic Cost (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Compensation And Retirement Disclosure [Abstract]	'	'	'
Service Cost - Benefits Earned During the Period	$1,129	$785	$561
Interest Cost of Projected Benefit Obligation	1,222	1,222	1,104
Expected Return on Plan Assets	-1,506	-1,371	-1,293
Recognized Net Actuarial Loss	921	980	242
Amortization of Prior-Service Cost	11	21	33
Net Periodic Pension Cost	$1,777	$1,637	$647

Schedule_of_Expected_Benefit_P

Schedule of Expected Benefit Payments (Detail) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Compensation And Retirement Disclosure [Abstract]	'
2015	$978
2016	1,065
2017	1,113
2018	1,184
2019	1,280
2020-2024	$8,307

Schedule_of_Assumptions_Used_i

Schedule of Assumptions Used in Net Periodic Benefit Cost and Benefit Obligations (Detail)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Compensation And Retirement Disclosure [Abstract]	'	'	'
Net Periodic Benefit Costs - Discount Rate	4.20%	4.56%	5.61%
Net Periodic Benefit Costs - Expected Return on Plan Assets	8.00%	8.00%	8.00%
Net Periodic Benefit Costs - Rate of Compensation Increase	3.50%	3.50%	3.50%
Benefit Obligations - Discount Rate	4.41%	4.20%	'
Benefit Obligations - Rate of Compensation Increase	3.50%	3.50%	'

Schedule_of_Pension_Plans_Weig

Schedule of Pension Plans Weighted-Average Asset Allocation and Range of Target Allocation (Detail)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]	'	'
Percentage of Plan Assets at March 31	100.00%	100.00%
Equity Securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Range of Target Allocation - Minimum	40.00%	'
Range of Target Allocation - Maximum	60.00%	'
Percentage of Plan Assets at March 31	65.00%	60.00%
Debt Securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Range of Target Allocation - Minimum	35.00%	'
Range of Target Allocation - Maximum	60.00%	'
Percentage of Plan Assets at March 31	30.00%	30.00%
Other [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Range of Target Allocation - Minimum	0.00%	'
Range of Target Allocation - Maximum	5.00%	'
Percentage of Plan Assets at March 31	5.00%	10.00%

Pension_and_Profit_Sharing_Pla2

Pension and Profit Sharing Plans - Additional information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2015	Mar. 31, 2015
	CompensationPlan			Salaried Employees [Member]	Hourly Employees [Member]	Scenario, Forecast [Member]	Scenario, Forecast [Member]	Scenario, Forecast [Member]
	Employee						Minimum [Member]	Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'	'	'
Current actuarial estimates contributions	$0.20	$0.10	$0.10	'	'	'	$0.50	$1
Employees fully vesting in employer's contributions made beginning in 2007, requirement years	'	'	'	'6 years	'3 years	'	'	'
Costs relating to employer discretionary contributions	4.5	3.3	2.5	'	'	'	'	'
Number of employees covered under multi-employer pension plans	60	'	'	'	'	'	'	'
Number of multi-employer plans	5	'	'	'	'	'	'	'
Collective bargaining agreement for employer covered under multi-employer plans, Expiration beginning date	30-Jun-14	'	'	'	'	'	'	'
Collective bargaining agreement for employer covered under multi-employer plans, Expiration ending date	31-Mar-17	'	'	'	'	'	'	'
Expenses related to Multi employer plans	$1	$0.20	'	'	'	$1	'	'

Schedule_of_Fair_Values_of_Def

Schedule of Fair Values of Defined Benefit Plans (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	$21,189	$18,693	$17,310
Equity Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	13,973	12,034	'
Fixed Income Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	6,526	5,752	'
Real Estate Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	130	287	'
Commodity Linked Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	170	420	'
Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	$390	$200	'

Schedule_of_Fair_Values_of_Def1

Schedule of Fair Values of Defined Benefit Plans Determined Using Fair Value Hierarchy of Inputs (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	$21,189	$18,693	$17,310
Equity Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	13,973	12,034	'
Fixed Income Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	6,526	5,752	'
Real Estate Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	130	287	'
Commodity Linked Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	170	420	'
Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	390	200	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	390	200	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Real Estate Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commodity Linked Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	390	200	'
Significant Other Observable Inputs (Level 2) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	20,799	18,493	'
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	13,973	12,034	'
Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	6,526	5,752	'
Significant Other Observable Inputs (Level 2) [Member] | Real Estate Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	130	287	'
Significant Other Observable Inputs (Level 2) [Member] | Commodity Linked Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	170	420	'
Significant Other Observable Inputs (Level 2) [Member] | Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Significant Unobservable Inputs (Level 3) [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income Securities [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Significant Unobservable Inputs (Level 3) [Member] | Real Estate Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Significant Unobservable Inputs (Level 3) [Member] | Commodity Linked Funds [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'
Significant Unobservable Inputs (Level 3) [Member] | Cash Equivalents [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Fair values of defined benefit plans	'	'	'

Quarterly_Results_unaudited_De

Quarterly Results (unaudited) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Quarterly Financial Information Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Revenues	$189,894	$228,812	$252,646	$227,044	$159,118	$164,743	$164,659	$154,042	'	'	'
Gross Profit	29,528	49,848	59,479	46,604	16,598	31,261	32,489	22,897	185,459	103,245	40,477
Earnings Before Income Taxes	29,767	48,833	58,688	44,516	10,756	27,301	26,125	19,914	181,804	84,096	21,912
Net Earnings	$22,618	$31,621	$39,903	$30,101	$7,833	$17,980	$17,953	$13,978	$124,243	$57,744	$18,732
Diluted Earnings Per Share	$0.45	$0.63	$0.80	$0.60	$0.16	$0.37	$0.40	$0.31	$2.49	$1.22	$0.42

Quarterly_Results_unaudited_Ad

Quarterly Results (unaudited) - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
		Facility
Quarterly Financial Information Disclosure [Abstract]	'	'	'	'	'
Additional maintenance costs	$4.50	$14	$77.40	$61.30	$37.60
Legal costs	1.3	'	'	'	'
Maintenance costs	1.5	'	'	'	'
Cost of natural gas	0.9	'	'	'	'
Number of new cement facilities	'	2	'	'	'
Additional acquisition and litigation expenses	'	$2.40	'	'	'