v3.26.1
Securities at amortized cost (AC) - Schedule of Reconciliation Of Expected Loss To Financial Assets At Amortized Cost (Details) - BRL (R$)
R$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period R$ 2,673,301  
Financial assets at end of period 2,880,511 R$ 2,673,301
Securities At Amortized Cost | Impairment | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (324) (183)
(Increase) / Reversal 82 (485)
Write-off 0 0
Financial assets at end of period (246) (324)
Securities At Amortized Cost | Impairment | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (125) (122)
(Increase) / Reversal (842) (123)
Write-off 0 0
Financial assets at end of period (761) (125)
Securities At Amortized Cost | Impairment | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (3,206) (549)
(Increase) / Reversal 1,860 (2,193)
Write-off 63 0
Financial assets at end of period (1,485) (3,206)
Securities At Amortized Cost | Impairment | Transfer to stage 2 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (10) (449)
Securities At Amortized Cost | Impairment | Transfer to stage 2 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (39) (166)
Securities At Amortized Cost | Impairment | Transfer to stage 2 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (1) (88)
Securities At Amortized Cost | Impairment | Cure from stage 2 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 39 166
Securities At Amortized Cost | Impairment | Cure from stage 2 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (10) (449)
Securities At Amortized Cost | Impairment | Cure from stage 2 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 46 (149)
Securities At Amortized Cost | Impairment | Transfer to stage 3 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (46) (149)
Securities At Amortized Cost | Impairment | Transfer to stage 3 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (175) (416)
Securities At Amortized Cost | Impairment | Transfer to stage 3 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (18) (13)
Securities At Amortized Cost | Impairment | Cure from stage 3 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 1 88
Securities At Amortized Cost | Impairment | Cure from stage 3 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 18 13
Securities At Amortized Cost | Impairment | Cure from stage 3 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 175 416
Securities At Amortized Cost | Government securities | Impairment | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (28) (36)
(Increase) / Reversal 20 8
Write-off 0 0
Financial assets at end of period (8) (28)
Securities At Amortized Cost | Government securities | Impairment | Transfer to stage 2 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 0 0
Securities At Amortized Cost | Government securities | Impairment | Cure from stage 2 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 0 0
Securities At Amortized Cost | Government securities | Impairment | Transfer to stage 3 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 0 0
Securities At Amortized Cost | Government securities | Impairment | Cure from stage 3 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 0  
Securities At Amortized Cost | Corporate securities | Impairment | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (296) (147)
(Increase) / Reversal 62 (493)
Write-off 0 0
Financial assets at end of period (238) (296)
Securities At Amortized Cost | Corporate securities | Impairment | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (125) (122)
(Increase) / Reversal (842) (123)
Write-off 0 0
Financial assets at end of period (761) (125)
Securities At Amortized Cost | Corporate securities | Impairment | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Financial assets at beginning of period (3,206) (549)
(Increase) / Reversal 1,860 (2,193)
Write-off 63 0
Financial assets at end of period (1,485) (3,206)
Securities At Amortized Cost | Corporate securities | Impairment | Transfer to stage 2 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (10) (449)
Securities At Amortized Cost | Corporate securities | Impairment | Transfer to stage 2 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (39) (166)
Securities At Amortized Cost | Corporate securities | Impairment | Transfer to stage 2 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (1) (88)
Securities At Amortized Cost | Corporate securities | Impairment | Cure from stage 2 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 39 166
Securities At Amortized Cost | Corporate securities | Impairment | Cure from stage 2 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (10) (449)
Securities At Amortized Cost | Corporate securities | Impairment | Cure from stage 2 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 46 (149)
Securities At Amortized Cost | Corporate securities | Impairment | Transfer to stage 3 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (46) (149)
Securities At Amortized Cost | Corporate securities | Impairment | Transfer to stage 3 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (175) (416)
Securities At Amortized Cost | Corporate securities | Impairment | Transfer to stage 3 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets (18) (13)
Securities At Amortized Cost | Corporate securities | Impairment | Cure from stage 3 | Stage 1    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 1 88
Securities At Amortized Cost | Corporate securities | Impairment | Cure from stage 3 | Stage 2    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets 18 13
Securities At Amortized Cost | Corporate securities | Impairment | Cure from stage 3 | Stage 3    
Disclosure of financial assets that are either past due or impaired [line items]    
Increase (decrease) through transfers, financial assets R$ 175 R$ 416