Description of the business and summary of significant accounting policies - Intangible assets (Details) - MXN ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Intangible assets
Impairment on intangible assets	$ 0	$ 0	$ 0
Software
Intangible assets
Useful life of intangible assets	5 years

The amount of impairment loss recognised in profit or loss for intangible assets other than goodwill. [Refer: Impairment loss recognised in profit or loss; Intangible assets other than goodwill]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2017-01-01
-Paragraph 118
-Subparagraph e
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e_iv&doctype=Standard
-URIDate 2017-03-09

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration