XML 178 R153.htm IDEA: XBRL DOCUMENT
v3.22.1

SEGMENT REPORTING - Summary (Details) - BRL (R$) R$ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Segment reporting as per business segments |  |  |  |
Net sales | R$ 78,345,081 | R$ 43,814,661 | R$ 39,644,010 |
Cost of sales | (57,527,721) | (37,884,102) | (35,440,726) |
GROSS PROFIT | 20,817,360 | 5,930,559 | 4,203,284 |
Selling, general and administrative expenses | (2,105,951) | (1,530,385) | (1,430,456) |
Other operating income (expenses) | 519,731 | 1,117,699 | 449,200 |
Eletrobras compulsory loan recovery | 1,391,280 | 0 | 0 |
Results in operations with subsidiary and joint ventures (note 3.4) | (162,913) | 0 | 0 |
Impairment of non-financial assets | 0 | (411,925) | 0 |
Impairment of financial assets | 357 | (64,132) | (21,044) |
Equity in earnings of unconsolidated companies | 563,158 | 152,569 | (17,050) |
INCOME BEFORE FINANCIAL INCOME (EXPENSES) AND TAXES | 21,023,022 | 5,194,385 | 3,183,934 |
Financial result, net | (750,454) | (1,698,707) | (1,509,214) |
INCOME BEFORE TAXES | 20,272,568 | 3,495,678 | 1,674,720 |
Income and social contribution taxes | (4,713,630) | (1,107,624) | (457,833) |
NET INCOME | 15,558,938 | 2,388,054 | 1,216,887 |
Depreciation/amortization | 2,658,561 | 2,499,104 | 2,074,295 |
Investments in associates and joint ventures | 3,340,775 | 2,271,629 | 1,812,399 | R$ 1,367,802
Total assets | 73,814,613 | 63,123,009 | 54,002,970 |
Total liabilities | 30,998,964 | 32,037,799 | 26,829,843 |
North America Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Impairment of non-financial assets |  | (342,355) |  |
Special Steel Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Impairment of non-financial assets |  | (69,570) |  |
Operating Segments | Brazil Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | 34,757,720 | 17,752,823 | 16,122,171 |
Cost of sales | (22,496,140) | (14,179,991) | (14,363,253) |
GROSS PROFIT | 12,261,580 | 3,572,832 | 1,758,918 |
Selling, general and administrative expenses | (781,942) | (562,019) | (539,344) |
Other operating income (expenses) | 137,649 | 31,500 | 295,818 |
Impairment of financial assets | 7,823 | (23,177) | (2,012) |
Equity in earnings of unconsolidated companies |  | (1,287) | (828) |
INCOME BEFORE FINANCIAL INCOME (EXPENSES) AND TAXES | 11,625,110 | 3,017,849 | 1,512,552 |
Financial result, net | (538,341) | (442,972) | (520,821) |
INCOME BEFORE TAXES | 11,086,769 | 2,574,877 | 991,731 |
Income and social contribution taxes | (2,769,495) | (652,126) | (214,400) |
NET INCOME | 8,317,274 | 1,922,751 | 777,331 |
Depreciation/amortization | 1,330,963 | 1,135,294 | 1,008,713 |
Investments in associates and joint ventures |  | 10,186 | 11,472 |
Total assets | 24,835,717 | 21,099,735 | 17,195,824 |
Total liabilities | 8,105,443 | 7,469,541 | 4,686,686 |
Operating Segments | North America Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | 27,838,000 | 17,458,318 | 14,656,028 |
Cost of sales | (22,416,578) | (16,212,757) | (13,351,209) |
GROSS PROFIT | 5,421,422 | 1,245,561 | 1,304,819 |
Selling, general and administrative expenses | (639,370) | (476,518) | (444,326) |
Other operating income (expenses) | 42,141 | 97,751 | 44,660 |
Impairment of non-financial assets |  | (342,355) |  |
Impairment of financial assets | (7,668) | (36,286) | (14,612) |
Equity in earnings of unconsolidated companies | 279,948 | 23,512 | (110,959) |
INCOME BEFORE FINANCIAL INCOME (EXPENSES) AND TAXES | 5,096,473 | 511,665 | 779,582 |
Financial result, net | (156,437) | (206,405) | (99,029) |
INCOME BEFORE TAXES | 4,940,036 | 305,260 | 680,553 |
Income and social contribution taxes | (1,092,146) | (178,447) | (188,458) |
NET INCOME | 3,847,890 | 126,813 | 492,095 |
Depreciation/amortization | 627,483 | 777,369 | 571,015 |
Investments in associates and joint ventures | 1,871,274 | 908,338 | 681,807 |
Total assets | 22,096,314 | 18,583,439 | 15,178,053 |
Total liabilities | 4,603,424 | 5,261,820 | 4,506,771 |
Operating Segments | South America Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | 6,856,766 | 3,831,406 | 3,259,253 |
Cost of sales | (5,332,853) | (3,015,189) | (2,762,157) |
GROSS PROFIT | 1,523,913 | 816,217 | 497,096 |
Selling, general and administrative expenses | (157,912) | (116,479) | (119,627) |
Other operating income (expenses) | 27,514 | 16,684 | 17,416 |
Impairment of financial assets | (1,073) | (2,436) | (1,906) |
Equity in earnings of unconsolidated companies | 268,291 | 99,341 | 66,468 |
INCOME BEFORE FINANCIAL INCOME (EXPENSES) AND TAXES | 1,660,733 | 813,327 | 459,447 |
Financial result, net | (314,473) | (60,787) | (163,459) |
INCOME BEFORE TAXES | 1,346,260 | 752,540 | 295,988 |
Income and social contribution taxes | (377,286) | (195,440) | (100,341) |
NET INCOME | 968,974 | 557,100 | 195,647 |
Depreciation/amortization | 213,001 | 142,143 | 120,462 |
Investments in associates and joint ventures | 1,071,333 | 976,046 | 748,392 |
Total assets | 7,113,706 | 5,448,922 | 4,562,604 |
Total liabilities | 2,376,176 | 1,360,098 | 996,876 |
Operating Segments | Special Steel Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | 10,980,191 | 6,096,471 | 6,701,900 |
Cost of sales | (9,427,221) | (5,794,666) | (6,167,502) |
GROSS PROFIT | 1,552,970 | 301,805 | 534,398 |
Selling, general and administrative expenses | (233,348) | (179,822) | (170,170) |
Other operating income (expenses) | 71,287 | 55,097 | 35,571 |
Impairment of non-financial assets |  | (69,570) |  |
Impairment of financial assets | 1,275 | (2,233) | (2,513) |
Equity in earnings of unconsolidated companies | 28,831 | 8,899 | 6,776 |
INCOME BEFORE FINANCIAL INCOME (EXPENSES) AND TAXES | 1,421,015 | 114,176 | 404,062 |
Financial result, net | (238,249) | (215,433) | (109,116) |
INCOME BEFORE TAXES | 1,182,766 | (101,257) | 294,946 |
Income and social contribution taxes | (287,292) | 13,229 | (60,749) |
NET INCOME | 895,474 | (88,028) | 234,197 |
Depreciation/amortization | 487,114 | 444,298 | 374,105 |
Investments in associates and joint ventures | 251,668 | 231,152 | 224,201 |
Total assets | 13,658,147 | 11,233,676 | 8,597,180 |
Total liabilities | 2,801,071 | 1,994,575 | 1,604,885 |
Eliminations and Adjustments |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | (2,087,596) | (1,324,357) | (1,095,342) |
Cost of sales | 2,145,071 | 1,318,501 | 1,203,395 |
GROSS PROFIT | 57,475 | (5,856) | 108,053 |
Selling, general and administrative expenses | (293,379) | (195,547) | (156,989) |
Other operating income (expenses) | 241,140 | 916,667 | 55,734 |
Eletrobras compulsory loan recovery | 1,391,280 |  |  |
Results in operations with subsidiary and joint ventures (note 3.4) | (162,913) |  |  |
Equity in earnings of unconsolidated companies | (13,912) | 22,104 | 21,493 |
INCOME BEFORE FINANCIAL INCOME (EXPENSES) AND TAXES | 1,219,691 | 737,368 | 28,291 |
Financial result, net | 497,046 | (773,110) | (616,789) |
INCOME BEFORE TAXES | 1,716,737 | (35,742) | (588,498) |
Income and social contribution taxes | (187,411) | (94,840) | 106,115 |
NET INCOME | 1,529,326 | (130,582) | (482,383) |
Investments in associates and joint ventures | 146,500 | 145,907 | 146,527 |
Total assets | 6,110,729 | 6,757,237 | 8,469,309 |
Total liabilities | 13,112,850 | 15,951,765 | 15,034,625 |
Eliminations and Adjustments | Brazil Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | (1,352,079) | (1,149,618) | (920,659) |
Eliminations and Adjustments | North America Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | (70,904) | (60,370) | (62,196) |
Eliminations and Adjustments | South America Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | (16,297) | (41) |  |
Eliminations and Adjustments | Special Steel Operation |  |  |  |
Segment reporting as per business segments |  |  |  |
Net sales | R$ (648,316) | R$ (114,328) | R$ (112,487) |

X
- Definition The amount of impairment loss recognised in profit or loss for cash, stocks, bonds. + References No definition available. + Details
Name: | ggb_ImpairmentLossRecognisedInProfitOrLossForCashAndStocksAndBonds
Namespace Prefix: | ggb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The entity's share of the profit (loss) of investments accounted for using the equity method. + References No definition available. + Details
Name: | ggb_ShareOfProfitLossOfInvestmentsAccountedForUsingEquityMethod
Namespace Prefix: | ggb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of a present economic resource controlled by the entity as a result of past events. Economic resource is a right that has the potential to produce economic benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2021-01-01 -Paragraph 93 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_a&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_c&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2021-01-01 -Paragraph 93 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_b&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2021-01-01 -Paragraph 93 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_e&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_55&doctype=Standard -URIDate 2021-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_Assets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of all expenses directly or indirectly attributed to the goods or services sold. Attributed expenses include, but are not limited to, costs previously included in the measurement of inventory that has now been sold, such as depreciation and maintenance of factory buildings and equipment used in the production process, unallocated production overheads, and abnormal amounts of production costs of inventories. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 99 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_99&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 103 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_103&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_CostOfSales
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of depreciation and amortisation expense. Depreciation and amortisation are the systematic allocations of depreciable amounts of assets over their useful lives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_e&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_e&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2021-01-01 -Paragraph B13 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B13_d&doctype=Appendix&subtype=B -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 102 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_102&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 99 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_99&doctype=Standard -URIDate 2021-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 104 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_104&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_DepreciationAndAmortisationExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfOperatingSegmentsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of income or cost associated with interest and other financing activities of the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_FinanceIncomeCost
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The gain on the recovery of loans and advances previously written off. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_GainOnRecoveryOfLoansAndAdvancesPreviouslyWrittenOff
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of revenue less cost of sales. [Refer: Cost of sales; Revenue] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 103 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_103&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_GrossProfit
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of impairment loss recognised in profit or loss for property, plant and equipment. [Refer: Impairment loss recognised in profit or loss; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2021-01-01 -Paragraph 73 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_e_v&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_98_a&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 26 -IssueDate 2021-01-01 -Paragraph 35 -Subparagraph b -Clause viii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=26&code=ifrs-tx-2021-en-r&anchor=para_35_b_viii&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -Subparagraph h -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_h&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2021-01-01 -Paragraph 79 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_79&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2021-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 82 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_d&doctype=Standard -URIDate 2021-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2021-01-01 -Paragraph 81 -Subparagraph c -Clause ii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_c_ii&doctype=Standard -URIDate 2021-03-24 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2021-01-01 -Paragraph B13 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B13_g&doctype=Appendix&subtype=B -URIDate 2021-03-24 + Details
Name: | ifrs-full_IncomeTaxExpenseContinuingOperations
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 24 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_24_a&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2021-01-01 -Paragraph B16 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B16&doctype=Appendix&subtype=B -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 54 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_e&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_InvestmentAccountedForUsingEquityMethod
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of a present obligation of the entity to transfer an economic resource as a result of past events. Economic resource is a right that has the potential to produce economic benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2021-01-01 -Paragraph 93 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_a&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2021-01-01 -Paragraph 93 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_b&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2021-01-01 -Paragraph 93 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_e&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_d&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23&doctype=Standard -URIDate 2021-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_55&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_Liabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of operating income (expense) that the entity does not separately disclose in the same statement or note. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_OtherOperatingIncomeExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The total of income less expenses from continuing and discontinued operations, excluding the components of other comprehensive income. [Refer: Other comprehensive income] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 7 -IssueDate 2021-01-01 -Paragraph 18 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_18_b&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 1 -IssueDate 2021-01-01 -Paragraph 24 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2021-en-r&anchor=para_24_b&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 1 -IssueDate 2021-01-01 -Paragraph 32 -Subparagraph a -Clause ii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2021-en-r&anchor=para_32_a_ii&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_b&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Note Effective on first application of IFRS 9 -Name IFRS -Number 4 -IssueDate 2021-01-01 -Paragraph 39L -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39L_e&doctype=Standard -URIDate 2021-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23&doctype=Standard -URIDate 2021-03-24 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Note Effective 2023-01-01 -Name IFRS -Number 17 -IssueDate 2021-01-01 -Paragraph 113 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_113_b&doctype=Standard -URIDate 2021-03-24 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 12 -IssueDate 2021-01-01 -Paragraph B10 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B -URIDate 2021-03-24 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 106 -Subparagraph d -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106_d_i&doctype=Standard -URIDate 2021-03-24 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 81A -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_81A_a&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_ProfitLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The profit (loss) before tax expense or income. [Refer: Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_b&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 103 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_103&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 102 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_102&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 5 -IssueDate 2021-01-01 -Paragraph 33 -Subparagraph b -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2021-en-r&anchor=para_33_b_i&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_ProfitLossBeforeTax
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The profit (loss) from operating activities of the entity. [Refer: Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 32 -IssueDate 2021-01-01 -Paragraph IE33 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=32&code=ifrs-tx-2021-en-r&anchor=para_IE33&doctype=Illustrative%20Examples -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_ProfitLossFromOperatingActivities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_a&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_a&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 32 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_32&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 33 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_33_a&doctype=Standard -URIDate 2021-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 34 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_34&doctype=Standard -URIDate 2021-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 82 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_a&doctype=Standard -URIDate 2021-03-24 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 103 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_103&doctype=Standard -URIDate 2021-03-24 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 102 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_102&doctype=Standard -URIDate 2021-03-24 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 5 -IssueDate 2021-01-01 -Paragraph 33 -Subparagraph b -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2021-en-r&anchor=para_33_b_i&doctype=Standard -URIDate 2021-03-24 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2021-01-01 -Paragraph B12 -Subparagraph b -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_v&doctype=Appendix&subtype=B -URIDate 2021-03-24 Reference 11: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 12 -IssueDate 2021-01-01 -Paragraph B10 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B -URIDate 2021-03-24 + Details
Name: | ifrs-full_Revenue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of expense relating to selling, general and administrative activities of the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_SellingGeneralAndAdministrativeExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The entity's share of the profit (loss) of associates and joint ventures accounted for using the equity method. [Refer: Associates [member]; Investments accounted for using equity method; Joint ventures [member]; Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 23 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_g&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2021-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_e&doctype=Standard -URIDate 2021-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Note Effective on first application of IFRS 9 -Name IFRS -Number 4 -IssueDate 2021-01-01 -Paragraph 39M -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39M_b&doctype=Standard -URIDate 2021-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 82 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_c&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_SegmentsAxis=ggb_NorthAmericaSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=ggb_SpecialSteelSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentConsolidationItemsAxis=ifrs-full_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=ggb_BrazilSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=ggb_SouthAmericaSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentConsolidationItemsAxis=ifrs-full_MaterialReconcilingItemsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |