Represents period for adjustments from purchase holdback liability for asset acquisition.

No definition available.

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Balance Type:	na
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- Definition

The amount of deduction from liabilities under an asset purchase agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959

+ Details

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- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of investment in marketable security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow for derivative instruments during the period, which are classified as financing activities, excluding those designated as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3505-108585

+ Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeForwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
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Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=gnss_AssetsAcquisitionOfAmikaMobileCorporationMember
Namespace Prefix:
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Note 6 - Fair Value Measurements (Details Textual) $ in Thousands, $ in Thousands					12 Months Ended
	Oct. 02, 2020 USD ($)	Oct. 02, 2020 CAD ($)	Oct. 01, 2020 USD ($)	Oct. 01, 2020 CAD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Aug. 31, 2020 CAD ($)
Marketable Securities, Total					$ 0
Derivative, Gain (Loss) on Derivative, Net, Total					$ (0)	$ (76)
Foreign Exchange Forward [Member]
Derivative, Notional Amount							$ 6,955
Payments for Derivative Instrument, Financing Activities			$ 5,281	$ 6,955
Derivative, Gain (Loss) on Derivative, Net, Total			$ (48)
Foreign Exchange Forward [Member] \| Accounts Payable and Accrued Liabilities [Member]
Derivative Liability, Current						$ 76
Assets Acquisition of Amika Mobile Corporation [Member]
Asset Purchase Agreement, Deduction From Liability	$ 787	$ 1,000
Asset Acquisition, Adjustments from Purchase Holdback Liability, Period (Year)	3 years	3 years