The percentage of ownership of common stock or equity participation in the investee accounted for under the cost method of accounting.

No definition available.

+ Details

Name:	grif_CostMethodInvestmentOwnershipPercentage
Namespace Prefix:	grif_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the total cash inflow associated with the sale of cost method investments.

+ References

No definition available.

+ Details

Name:	grif_TotalProceedsFromSaleOfCostMethodInvestments
Namespace Prefix:	grif_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This item represents the gain (loss) realized during the period from the sale of investments accounted for under the cost method of accounting and any losses recognized thereon for impairments of other than a temporary nature.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(c),9(a))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 7
-Subparagraph c, d
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 9
-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfCostMethodInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=grif_SheminNurseriesHoldingCorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investments - Shemin Nurseries Hodling Corp. (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2012
Investments
Pre Tax Gain on sale of investment		$ 3,397
SNHC
Investments
Equity interest in cost method investment (as a percent)			14.00%
Total cash proceeds from sale of investment	$ 3,418
Pre Tax Gain on sale of investment		$ 3,397