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Represents the cash received upon completion of the sewer line to service the land that was sold.

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Represents the estimated pretax gain on sale that would be recognized after all costs are incurred and total revenue is recognized.

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Funds held in escrow for the acquisition of a replacement property, as a part of the Section 1031 like-kind exchange.

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Area of land sold.

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No definition available.

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Represents the percentage of total cost incurred, related to the sale of real estate property.

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No definition available.

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Represents the pretax gain on sale of real estate property recognized based on the percentage of total costs incurred related to sale.

+ References

No definition available.

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Amount of real estate depreciation expense for the period.

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No definition available.

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Represents the percentage of revenue and pretax gain from sale of real estate property recognized based on the percentage of total costs incurred related to sale.

+ References

No definition available.

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Represents the revenue from modification in agreement related to the sale of real estate property.

+ References

No definition available.

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Represents the sale price of land.

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No definition available.

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Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property.

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Amount of interest capitalized during the period.

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Revenue from the sale of land in the reporting period.

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The cash inflow from the sale of land held for investment; excludes sales of land held as inventory or productive use.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Useful life on which depreciation was computed for entities with a substantial portion of business acquiring and holding investment real estate, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The cumulative amount of depreciation for real estate property held for investment purposes.

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Real Estate Assets (Details) (USD $)	3 Months Ended		12 Months Ended			24 Months Ended
Real Estate Assets (Details) (USD $)	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	Dec. 01, 2012	Nov. 30, 2013	Jan. 08, 2014
Real estate assets
Real estate assets, gross	$ 209,284,000	$ 192,268,000	$ 209,284,000	$ 192,268,000		$ 192,268,000
Accumulated depreciation	(74,762,000)	(61,078,000)	(74,762,000)	(61,078,000)		(61,078,000)
Real estate assets, net	134,522,000us-gaap_RealEstateInvestmentPropertyNet	131,190,000us-gaap_RealEstateInvestmentPropertyNet	134,522,000us-gaap_RealEstateInvestmentPropertyNet	131,190,000us-gaap_RealEstateInvestmentPropertyNet		131,190,000us-gaap_RealEstateInvestmentPropertyNet
Depreciation expense			5,747,000grif_RealEstateDepreciationExpense	5,545,000grif_RealEstateDepreciationExpense	5,237,000grif_RealEstateDepreciationExpense
Capitalized interest			580,000us-gaap_InterestCostsCapitalized	71,000us-gaap_InterestCostsCapitalized	596,000us-gaap_InterestCostsCapitalized
Property, Plant and Equipment, Gross	1,218,000us-gaap_PropertyPlantAndEquipmentGross	15,998,000us-gaap_PropertyPlantAndEquipmentGross	1,218,000us-gaap_PropertyPlantAndEquipmentGross	15,998,000us-gaap_PropertyPlantAndEquipmentGross		15,998,000us-gaap_PropertyPlantAndEquipmentGross
Accumulated depreciation	(988,000)	(14,048,000)	(988,000)	(14,048,000)		(14,048,000)
Sales
Proceeds from land sale deposited in escrow		8,860,000		8,860,000		8,860,000
Revenue from sale of land	1,831,000us-gaap_LandSales	2,668,000us-gaap_LandSales
Deferred revenue that will be recognized as the construction of roadways connecting the land with existing town roads	8,349,000us-gaap_DeferredRevenue	8,467,000us-gaap_DeferredRevenue	8,349,000us-gaap_DeferredRevenue	8,467,000us-gaap_DeferredRevenue		8,467,000us-gaap_DeferredRevenue
Connecticut production nursery \| Imperial's landscape nursery business
Real estate assets
Real estate assets, net	1,444,000		1,444,000
Property, Plant and Equipment, Gross							11,485,000
Accumulated depreciation							(9,850,000)
Windsor undeveloped land sale
Sales
Deferred revenue that will be recognized as the construction of roadways connecting the land with existing town roads	3,195,000		3,195,000
Held for Sale
Real estate assets
Real estate assets, gross	9,943,000	1,104,000	9,943,000	1,104,000		1,104,000
Land
Real estate assets
Real estate assets, gross	17,955,000	17,507,000	17,955,000	17,507,000		17,507,000
Land \| Tradeport Undeveloped land sale
Sales
Number of acres sold					93
Proceeds from land sale deposited in escrow					6,929,000
Revenue from sale of land			2,668,000	2,474,000
Pretax gain on land sale			1,990,000	2,109,000
Proceeds from sale of undeveloped land					7,000,000
Pretax gain from sale of land recognized					3,942,000	6,051,000
Revenue from an amended agreement related to land sale				177,000
Cash received upon completion of the sewer line to service the land				177,000
Land \| Windsor undeveloped land sale
Sales
Number of acres sold		90		90		90
Sale price		9,000,000		9,000,000		9,000,000
Area of land portion of which is to be sold (in acres)		253		253		253
Proceeds from land sale deposited in escrow		8,860,000		8,860,000		8,860,000
Percentage of cost incurred on sale of land	64.00%		64.00%
Percentage of total revenue and pretax gain on sale have been recognized			64.00%
Revenue from sale of land			3,105,000
Pretax gain on land sale			2,358,000
Deferred revenue that will be recognized as the construction of roadways connecting the land with existing town roads	3,195,000		3,195,000
Estimated pretax gain on sale that would be recognized after incurring total costs and recognizing total revenue			6,754,000
Land \| Held for Sale
Real estate assets
Real estate assets, gross	286,000	30,000	286,000	30,000		30,000
Land improvements
Real estate assets
Real estate assets, gross	18,527,000	15,529,000	18,527,000	15,529,000		15,529,000
Land improvements \| Minimum
Real estate assets
Estimated Useful Lives			10 years
Land improvements \| Maximum
Real estate assets
Estimated Useful Lives			30 years
Buildings and improvements
Real estate assets
Real estate assets, gross	135,857,000	122,057,000	135,857,000	122,057,000		122,057,000
Buildings and improvements \| Minimum
Real estate assets
Estimated Useful Lives			10 years
Buildings and improvements \| Maximum
Real estate assets
Estimated Useful Lives			40 years
Tenant improvements
Real estate assets
Real estate assets, gross	14,820,000	16,126,000	14,820,000	16,126,000		16,126,000
Machinery and equipment
Real estate assets
Real estate assets, gross	11,810,000	4,188,000	11,810,000	4,188,000		4,188,000
Machinery and equipment \| Minimum
Real estate assets
Estimated Useful Lives			3 years
Machinery and equipment \| Maximum
Real estate assets
Estimated Useful Lives			20 years
Development costs
Real estate assets
Real estate assets, gross	10,315,000	16,861,000	10,315,000	16,861,000		16,861,000
Development costs \| Held for Sale
Real estate assets
Real estate assets, gross	$ 9,657,000	$ 1,074,000	$ 9,657,000	$ 1,074,000		$ 1,074,000