Name:	gff_BusinessAcquisitionPurchasePriceAllocationCustomerRelationshipsExpectedTaxDeductibleAmount
Namespace Prefix:	gff_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The amount of goodwill and intangible assets arising from a business combination that is expected to be deductible for tax purposes.

No definition available.

Name:	gff_BusinessAcquisitionPurchasePriceAllocationGoodwillAndIntangibleAssetsExpectedTaxDeductibleAmount
Namespace Prefix:	gff_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

The amount of tradenames arising from a business combination that is expected to be deductible for tax purposes.

No definition available.

Name:	gff_BusinessAcquisitionPurchasePriceAllocationTradenamesExpectedTaxDeductibleAmount
Namespace Prefix:	gff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Description of amortization period of goodwill.

No definition available.

Name:	gff_DescriptionOfAmortizationPeriodOfGoodwill
Namespace Prefix:	gff_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Description for amortization period of trade names reported.

No definition available.

Name:	gff_TradenamesAmortizationPeriodDescription
Namespace Prefix:	gff_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 53

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 52

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph k

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.