Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Feb. 29, 2016	Aug. 31, 2015	Feb. 28, 2015
Condensed Consolidated Balance Sheets [Abstract]
Receivables, allowance, current	$ 7,987,000	$ 9,706,000	$ 2,517,000
Receivables, allowance, noncurrent	$ 0	$ 0	$ 2,007,000
Preferred stock, par value	$ 1	$ 1	$ 1
Preferred stock, authorized	2,000,000	2,000,000	2,000,000
Preferred stock, outstanding	0	0	0
Preferred stock, issued	0	0	0
Common stock, par value	$ 1	$ 1	$ 1
Common stock, authorized	25,000,000	25,000,000	25,000,000
Common stock, issued	18,713,000	18,684,000	18,675,000
Treasury stock, shares	7,864,000	7,394,000	6,802,000

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5074-111524

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A valuation allowance for receivables due to an Entity for more than one year from the balance sheet date that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 4
-Article 5

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