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Represents the length of each fiscal year.

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No definition available.

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Represents the length of period for specific number of quarters.

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No definition available.

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The current and non-current portion of the amount recognized for uncertain tax positions as of the balance sheet date.

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No definition available.

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Represents the number of buildings built by the entity.

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No definition available.

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Represents the number of quarters in specified length of period.

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No definition available.

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- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

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

-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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

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Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Nov. 30, 2014 building	Nov. 30, 2013 item	Dec. 01, 2012
Fiscal Year
Length of fiscal year	12 months
Number of quarters in 13 weeks period		4
Length of period for 4 quarters		91 days
Cash and Cash Equivalents
Money market funds invested in U.S. Treasury obligations	$ 16,433us-gaap_MoneyMarketFundsAtCarryingValue	$ 175us-gaap_MoneyMarketFundsAtCarryingValue
Impairment of Investments in Long Lived Assets
Impairment losses	0us-gaap_AssetImpairmentCharges	0us-gaap_AssetImpairmentCharges	0us-gaap_AssetImpairmentCharges
Income Taxes
Accrual for uncertain income tax positions	$ 0
Risks and uncertainties
Number of buildings built	2grif_NumberOfBuildingsBuilt
Minimum
Fiscal Year
Length of fiscal year		364 days
Maximum
Fiscal Year
Length of fiscal year		371 days