XML 99 R74.htm IDEA: XBRL DOCUMENT
v3.22.1

INVENTORIES - Allowance for adjustment to net realizable value of inventories (Details) - Inventories - BRL (R$) R$ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Allowance for adjustment to net realizable value of inventories |  |  |
Balance, beginning of year | R$ (6,119) | R$ (39,308) | R$ (13,704)
Provision for the year | (6,331) | (6,562) | (46,693)
Reversal of adjustments to net realizable value | 9,143 | 47,259 | 22,028
Exchange rate variation | (68) | (7,508) | (939)
Balance, end of year | R$ (3,375) | R$ (6,119) | R$ (39,308)

X
- Definition The amount of additional allowance for credit losses of financial assets recognised in profit or loss. [Refer: Allowance account for credit losses of financial assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Note Expiry date 2023-01-01 -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_16&doctype=Standard&book=b -URIDate 2021-03-24 + Details
Name: | ifrs-full_AdditionalAllowanceRecognisedInProfitOrLossAllowanceAccountForCreditLossesOfFinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of an allowance account used to record impairments to financial assets due to credit losses. [Refer: Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2023-01-01 -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_16&doctype=Standard&book=b -URIDate 2021-03-24 + Details
Name: | ifrs-full_AllowanceAccountForCreditLossesOfFinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The increase (decrease) in an allowance account for credit losses of financial assets resulting from the net exchange differences arising when the financial statements are translated from the functional currency into a different presentation currency, including the translation of a foreign operation into the presentation currency of the reporting entity. [Refer: Allowance account for credit losses of financial assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Note Expiry date 2023-01-01 -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_16&doctype=Standard&book=b -URIDate 2021-03-24 + Details
Name: | ifrs-full_IncreaseDecreaseThroughNetExchangeDifferencesAllowanceAccountForCreditLossesOfFinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | ifrs-full_ReconciliationOfChangesInAllowanceAccountForCreditLossesOfFinancialAssetsAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The decrease in an allowance account for credit losses of financial assets resulting from the reversal of impairment. [Refer: Allowance account for credit losses of financial assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Note Expiry date 2023-01-01 -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_16&doctype=Standard&book=b -URIDate 2021-03-24 + Details
Name: | ifrs-full_ReversalAllowanceAccountForCreditLossesOfFinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ClassesOfAssetsAxis=ggb_IfrsInventoriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |