Schedule III-Real Estate and Accumulated Depreciation (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2012
Cost
Balance at beginning of year	$ 192,268us-gaap_RealEstateGrossAtCarryingValue		$ 168,160us-gaap_RealEstateGrossAtCarryingValue
Changes during the year:
Additions to real estate assets	16,680grif_RealEstateAdditions	13,769grif_RealEstateAdditions	13,557grif_RealEstateAdditions
Reclassification to real estate held for sale	(9,236)	(962)	(693)
Writeoff of fully depreciated assets	(1,913)	(1,210)	(353)
Reclassification of real estate assets from property and equipment	11,485
Balance at end of year	209,284us-gaap_RealEstateGrossAtCarryingValue	192,268us-gaap_RealEstateGrossAtCarryingValue	180,671us-gaap_RealEstateGrossAtCarryingValue
Reserve
Balance at beginning of year	(61,078)		(51,865)
Changes during the year:
Additions to reserve charged to costs and expense	(5,747)	(5,545)	(5,237)
Reclassification to real estate held for sale		1	5
Writeoff of fully depreciated assets	1,913	1,210	353
Reclassification of real estate assets from property and equipment	(9,850)
Balance at end of year	$ (74,762)	$ (61,078)	$ (56,744)

Represents the reclassification to real estate held for sale.

No definition available.

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- Definition

Represents the writeoff of fully depreciated assets.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of increase in real estate investments during the period.

+ References

No definition available.

+ Details

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- Definition

Amount of pure depreciation expense for the period without adjustments such as write off of assets.

+ References

No definition available.

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- Definition

Represents the real estate investments reclassified as held for sale during the period.

+ References

No definition available.

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- Definition

Represents the writeoff of fully depreciated real estate assets during the period.

+ References

No definition available.

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- Definition

Represent value of asset reclassified to of real estate assets from property and equipment.

+ References

No definition available.

+ Details

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- Definition

Represents the related accumulated deprecation of asset Reclassified to real estate assets from property and equipment.

+ References

No definition available.

+ Details

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- Definition

Amount of accumulated depreciation pertaining to real estate investments for entities with a substantial portion of business acquiring and holding investment real estate.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 970

-SubTopic 360

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-28.FN4)

-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule III)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule III

-Article 5

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- Definition

Amount, before accumulated depreciation, of real estate investments for entities with a substantial portion of business acquiring and holding investment real estate.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule III)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule III

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 970

-SubTopic 360

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-28.4)

-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

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