Nature of operations, Labor reform on holidays (Details)	12 Months Ended
Dec. 31, 2022
Nature of operations [Abstract]
Number of additional days employee vacation days extended	6 days

The number of additional days extending the lawfully decreed vacation period for employees.

No definition available.

Name:	gtmay_VacationPeriodForEmployeesPeriodOfExtension
Namespace Prefix:	gtmay_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration