XML 101 R104.htm IDEA: XBRL DOCUMENT
v3.19.3

REPORTABLE SEGMENTS (Details) - Schedule of Revenue by Geographic Region - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2017
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated revenue | $ 574,164 | $ 574,970 | $ 549,633 | $ 510,522 | $ 545,505 | $ 516,550 | $ 478,560 | $ 437,303 | $ 2,209,289 | $ 1,977,918 | $ 1,524,997
United States [Member] |  |  |  |  |  |  |  |  |  |  |
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated revenue |  |  |  |  |  |  |  |  |  | 1,521,187 | 1,164,958
Europe [Member] |  |  |  |  |  |  |  |  |  |  |
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated revenue |  |  |  |  |  |  |  |  |  | 102,814 | 67,048
Canada [Member] |  |  |  |  |  |  |  |  |  |  |
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated revenue |  |  |  |  |  |  |  |  |  | 123,341 | 106,080
AUSTRALIA |  |  |  |  |  |  |  |  |  |  |
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated revenue |  |  |  |  |  |  |  |  |  | 166,980 | 124,757
All Other Countries [Member] |  |  |  |  |  |  |  |  |  |  |
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated revenue |  |  |  |  |  |  |  |  |  | $ 63,596 | $ 62,154

X
- References No definition available. + Details
Name: | gff_REPORTABLESEGMENTSDetailsScheduleofSegmentInformationbyGeographicRegionLineItems
Namespace Prefix: | gff_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045 + Details
Name: | us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=srt_EuropeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_AU
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=gff_AllOtherCountriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |