Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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The net amount of operating interest income (expense).

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Industry Segment Information (Schedule Of Segment Reporting Information, By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Aug. 31, 2017	May 31, 2017	Feb. 28, 2017	Nov. 30, 2016	Aug. 31, 2016	May 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Segment Reporting Information [Line Items]
Total operating revenues	$ 131,937	$ 151,533	$ 124,125	$ 110,390	$ 132,897	$ 141,319	$ 120,573	$ 121,622	$ 517,985	$ 516,411	$ 560,181
Segment operating income									40,201	34,375	50,695
Unallocated general and administrative expenses									(46,959)	(56,419)	(52,261)
Interest and other income (expense), net									(4,486)	(5,087)	(3,944)
Earnings before income taxes	10,547	$ 16,197	$ 7,636	$ 1,335	11,020	$ 14,065	$ (6,193)	$ 10,396	35,715	29,288	46,751
Capital expenditures									8,863	11,496	15,244
Depreciation and amortization									16,678	16,881	16,412
Assets	506,032				487,515				506,032	487,515	522,595
Irrigation [Member]
Segment Reporting Information [Line Items]
Total operating revenues									418,041	421,641	451,205
Capital expenditures									6,313	8,375	12,406
Depreciation and amortization									11,840	11,774	11,000
Assets	337,446				332,294				337,446	332,294	316,220
Infrastructure [Member]
Segment Reporting Information [Line Items]
Total operating revenues									99,944	94,770	108,976
Capital expenditures									1,562	2,977	2,671
Depreciation and amortization									4,452	4,648	4,966
Assets	80,187				81,160				80,187	81,160	79,436
Corporate [Member]
Segment Reporting Information [Line Items]
Capital expenditures									988	144	167
Depreciation and amortization									386	459	446
Assets	$ 88,399				$ 74,061				88,399	74,061	126,939
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment operating income									62,905	67,767	72,314
Operating Segments [Member] \| Irrigation [Member]
Segment Reporting Information [Line Items]
Segment operating income									42,774	49,232	52,065
Operating Segments [Member] \| Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment operating income									20,131	18,535	20,249
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Unallocated general and administrative expenses									$ (22,704)	$ (33,392)	$ (21,619)