Shareholders' equity (Details) - BRL (R$) R$ / shares in Units, R$ in Millions |
1 Months Ended | 9 Months Ended | 12 Months Ended | ||||||
|---|---|---|---|---|---|---|---|---|---|
May 09, 2022 |
Oct. 14, 2021 |
Jul. 27, 2022 |
Apr. 28, 2022 |
Feb. 21, 2022 |
Sep. 30, 2022 |
Sep. 30, 2021 |
Dec. 31, 2021 |
Jun. 27, 2022 |
|
| Shareholders' equity (Details) [Line Items] | |||||||||
| Capital stock | R$ 1,258 | R$ 788 | |||||||
| Number of shares issued (in Shares) | 1,348,332,666 | 1,346,674,477 | |||||||
| Authorized share capital increased (in Shares) | 2,000,000,000 | ||||||||
| Capital stock increase amount | R$ 464 | ||||||||
| Reserve amount | R$ 631 | R$ 29 | R$ 18 | ||||||
| Tax incentives reserve amount | R$ 540 | R$ 709 | |||||||
| Shares issued percentage | 2.00% | ||||||||
| Description of Options Granted | The fair value of each option granted is estimated on the grant date, by using the options pricing model “Black&Scholes” taking into account the following assumptions for B8, C8, B9 and C9 series: (a) expectation of dividends of 1.28% (series 8) and 1.20% (series 9); (b) expectation of volatility nearly 37.06% (series 8) and 37.29% (series 9); (c) the weighted average interest rate without risk of 7.66% (series 8) and 12.18% (series 9), and (d) exit rate of approximately 8.00% in both series. The expectation of remaining average life of the series outstanding on September 30, 2022, is 20 months (series 8) and 32 months (series 9). The weighted average fair value of options granted on September 30, 2022, was R$17.21 and R$7.69 (B8 and C8 respectively), and R$15.27 and R$7.35 (B9 and C9 respectively). | ||||||||
| Amounts Recorded InStatement Of Operation | R$ 9 | R$ 1 | |||||||
| Annual General Meeting [Member] | |||||||||
| Shareholders' equity (Details) [Line Items] | |||||||||
| Dividend amount | R$ 224 | R$ 56 | |||||||
| Tax credit for investment subsidy | R$ 709 | ||||||||
| Capital Interest amount | R$ 168 | ||||||||
| Common stock per share (in Brazil Real per share) | R$ 125,038.407679398000000 | ||||||||
| Board of Directors [Member] | |||||||||
| Shareholders' equity (Details) [Line Items] | |||||||||
| Number of shares issued (in Shares) | 298,919 | 1,119,515 | 239,755 | ||||||
| Capital stock increase amount | R$ 2 | R$ 3 | R$ 1 | ||||||