Summary of Operating Results and Certain Other Financial Data for Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Segment Reporting Information [Line Items]
NET SALES	$ 208,892	$ 167,693	$ 441,974	$ 342,216
Segment operating profit (loss)	7,580	6,970	34,278	17,482
Corporate	(7,672)	(10,359)	(16,399)	(20,626)
Interest	(17,423)	(7,457)	(34,794)	(15,235)
LOSS BEFORE INCOME TAXES FROM CONTINUING OPERATIONS	(17,515)	(10,846)	(16,915)	(18,379)
Depreciation, depletion and amortization			39,433	28,543
Capital expenditures	11,922	14,326	24,420	46,651
Cement Segment
Segment Reporting Information [Line Items]
Sales to external customers	85,093	80,991	182,580	168,118
Intersegment sales	17,270	10,452	34,531	20,530
Segment operating profit (loss)	3,694	6,057	17,687	14,479
Capital expenditures	6,793	11,052	16,415	40,785
Aggregates
Segment Reporting Information [Line Items]
Sales to external customers	30,637	33,899	67,763	69,299
Intersegment sales	11,923	6,313	23,955	11,894
Segment operating profit (loss)	5,390	3,520	11,977	7,518
Capital expenditures	2,021	2,278	2,681	2,601
Consumer Products
Segment Reporting Information [Line Items]
Sales to external customers	93,163	52,803	191,631	104,799
Intersegment sales	8	62	60	111
Segment operating profit (loss)	(1,504)	(2,607)	4,614	(4,515)
Capital expenditures	1,351	351	2,801	2,246
Intersegment Elimination
Segment Reporting Information [Line Items]
NET SALES	(29,202)	(16,827)	(58,546)	(32,535)
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	1,757	645	2,523	1,019
Cement
Segment Reporting Information [Line Items]
NET SALES	77,586	72,169	164,753	149,404
Stone, Sand And Gravel
Segment Reporting Information [Line Items]
NET SALES	19,999	21,428	43,684	43,997
Ready-Mix Concrete
Segment Reporting Information [Line Items]
NET SALES	93,448	52,712	191,632	104,582
Other products
Segment Reporting Information [Line Items]
NET SALES	1,929	2,648	5,617	5,515
Delivery Fees
Segment Reporting Information [Line Items]
NET SALES	15,930	18,736	36,288	38,718
Segment, Continuing Operations
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	19,568	13,986	39,462	27,860
Segment, Continuing Operations \| Cement Segment
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	13,077	8,429	26,120	16,893
Segment, Continuing Operations \| Aggregates
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	2,882	3,347	6,073	6,674
Segment, Continuing Operations \| Consumer Products
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	3,387	1,981	6,805	3,847
Segment, Continuing Operations \| Corporate
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	$ 222	$ 229	$ 464	$ 446

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

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The cost of borrowed funds accounted for as interest that was charged against earnings during the period.

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The net result for the period of deducting operating expenses from operating revenues.

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The aggregate amount of other expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating expense recognized during the period. Such amounts may include: (a) unusual costs, (b) loss on foreign exchange transactions, (c) losses on securities (net of profits), and (d) miscellaneous other expense items.

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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Amount of revenue from external customers for the reportable segment. Such disclosure is presented if the amount is: (a) included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.

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Amount of revenue from transactions with other operating segments of the same entity.

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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