Employee Benefits and Private Pension Plan - Significant actuarial assumptions adopted (Detail)	Dec. 31, 2020	Dec. 31, 2019
Employee benefits and private pension plan details 3 [abstract]
Discount rate for the actuarial obligation at present value	8.22%	8.79%
Average projected salary growth rate	7.07%	7.64%
Inflation rate (long term)	3.25%	3.80%
Growth rate of medical services	7.38%	7.95%

The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2019-01-01
-Paragraph 144
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2019-en-r&anchor=para_144&doctype=Standard
-URIDate 2019-03-27

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