Employee benefits - Analysis of net period cost (Details) - MXN ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee benefits
Current service cost	$ 8,611	$ 8,449	$ 8,214
Interest cost on benefit obligation	2,585	2,630	1,872
Net period cost	$ 11,196	$ 11,079	$ 10,086

The amount of post-employment benefit expense included in profit or loss relating to defined benefit plans. [Refer: Profit (loss); Defined benefit plans [member]] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from expense (income) in profit or loss]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Name:	ifrs-full_PostemploymentBenefitExpenseDefinedBenefitPlans
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration