26. EXPENSES BY NATURE (Details) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ExpenseByNatureLineItems [Line Items]
Expense, net	R$ (21,633,776)	R$ (20,117,134)	R$ (18,863,368)
Classified as:
Cost of sales	19,124,901	17,263,264	16,105,657
Selling expenses	(2,004,417)	(2,342,805)	(2,263,688)
General and administrative expenses	(504,458)	(511,065)	(494,023)
Total	(21,633,776)	(20,117,134)	(18,863,368)
Raw materials and inputs [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(6,928,517)	(7,287,933)	(6,759,275)
Labor cost [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(3,187,428)	(2,807,280)	(2,743,460)
Supplies [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(2,150,452)	(1,981,547)	(1,782,576)
Maintenance cost Services and materials [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(1,340,255)	(1,340,135)	(1,326,894)
Outsourcing services [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(2,217,657)	(2,392,626)	(2,368,387)
Freights [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(216,506)	(334,509)	(109,756)
Distribution freights [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(1,421,079)	(1,787,979)	(1,692,785)
Depreciation amortization and depletion [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	(2,421,458)	(1,421,704)	(1,175,107)
Others [member]
ExpenseByNatureLineItems [Line Items]
Expense, net	R$ (1,750,424)	R$ (763,421)	R$ (905,128)

The amount of expenses that the entity classifies as being administrative.

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The amount of costs relating to expenses directly or indirectly attributed to the goods or services sold, which may include, but are not limited to, costs previously included in the measurement of inventory that has now been sold, unallocated production overheads and abnormal amounts of production costs of inventories.

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The amount of operating expense excluding the cost of sales. [Refer: Cost of sales]

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The amount of expense relating to the marketing and selling of goods or services.

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