Trade Notes and Accounts Receivable, Net - Provision Matrix Arising from Telecommunications and Project Business (Parenthetical) (Detail)	Dec. 31, 2019
Project Business [Member] \| Bottom of Range [Member]
Disclosure of financial assets that are either past due or impaired [Line Items]
Expected credit loss rate	50.00%

The rate of expected credit losses, calculated as percentage of the gross carrying amount. Expected credit losses are the weighted average of credit losses with the respective risks of a default occurring as the weights.

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Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant