Revenue Recognition and Contracts with Customers - Additional Information (Details)	12 Months Ended
Dec. 31, 2022
Revenue Recognition And Contracts With Customers [Line Items]
Performance obligation satisfied, period	1 month
Cash advances and unbilled receivables settlement, period	3 months
Performance obligation, minimum expected term period to disclose value	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Recognition And Contracts With Customers [Line Items]
Performance obligation expected to be satisfied, period	1 year
Maximum
Revenue Recognition And Contracts With Customers [Line Items]
Performance obligation satisfied over time, percentage	1.00%

Contract with customer cash advances and unbilled receivables settlement period.

No definition available.

Name:	gtx_RevenueContractWithCustomerCashAdvancesAndUnbilledReceivablesSettlementPeriod
Namespace Prefix:	gtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue performance obligation satisfied over time percentage.

+ References

No definition available.

+ Details

Name:	gtx_RevenuePerformanceObligationSatisfiedOverTimePercentage
Namespace Prefix:	gtx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Revenue recognition and contracts with customers.

+ References

No definition available.

+ Details

Name:	gtx_RevenueRecognitionAndContractsWithCustomersLineItems
Namespace Prefix:	gtx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue, Remaining Performance Obligation, Expected Term Period To Disclose Value, Minimum

+ References

No definition available.

+ Details

Name:	gtx_RevenueRemainingPerformanceObligationMinimumExpectedTermPeriodToDiscloseValue
Namespace Prefix:	gtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue, Remaining Performance Obligation, Timing of Satisfaction, Period

+ References

No definition available.

+ Details

Name:	gtx_RevenueRemainingPerformanceObligationTimingOfSatisfactionPeriod
Namespace Prefix:	gtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130556-203045

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2023-01-01
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: