Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
May 31, 2014	May 31, 2013	May 31, 2014 segment	May 31, 2013
Segment Information [Abstract]
Reportable business segments			2
Company Drive-Ins	$ 111,014	$ 108,445	$ 286,361	$ 285,607
Franchise Operations	39,876	36,922	99,280	95,273
Unallocated revenues	1,297	1,267	2,939	2,903
Total revenues	152,187	146,634	388,580	383,783
Company Drive-Ins	19,297	18,389	41,750	39,673
Franchise Operations	39,876	36,922	99,280	95,273
Unallocated income	1,169	1,409	2,976	3,256
Selling, general and administrative	(17,639)	(16,943)	(50,530)	(48,540)
Depreciation and amortization	(11,022)	(9,783)	(31,087)	(30,447)
Income from operations	31,681	29,994	62,389	59,215
Net interest expense	(6,216)	(7,017)	(18,722)	(22,323)
Income before income taxes	$ 25,465	$ 22,977	$ 43,667	$ 36,892

Company drive-ins, operating income

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- Definition

Franchise Operations Income From Operations

+ References

No definition available.

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- Definition

Franchise Operations, Revenues

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No definition available.

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- Definition

Unallocated income

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No definition available.

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- Definition

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

The net amount of operating interest income (expense).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.10)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 10

-Article 9

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

Revenues from the sale of other goods or rendering of other services, not elsewhere specified in the taxonomy; net of (reduced by) sales adjustments, returns, allowances, and discounts.

+ References

+ Details

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- Definition

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).

+ References

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- Definition

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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- Details

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- Definition

The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.4)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 4

-Article 5

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 330

-SubTopic 10

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6386349&loc=d3e3636-108311

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