v3.26.1
Fair value of financial assets and liabilities - Valuation methods of financial assets and liabilities measured at fair value and classified into Level 3 and significant but unobservable inputs (Details)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Debt securities | LSMC(Hull-White) | Volatility    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as volatility increases. Variation of fair value increases as volatility increases.
Debt securities | LSMC(Hull-White) | Volatility | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0.2345 0.2809
Debt securities | LSMC(Hull-White) | Volatility | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0.3748 0.8835
Loans | DCF model | Discount rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as discount rate decreases. Fair value increases as discount rate decreases.
Loans | DCF model | Discount rate | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0.007 0.0417
Loans | DCF model | Discount rate | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0.0526 0.0598
Equity related derivative assets | Option valuation model and others | Discount rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0.1688  
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as discount rate decreases. Fair value increases as discount rate decreases.
Equity related derivative assets | Option valuation model and others | Discount rate | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets   0.0394
Equity related derivative assets | Option valuation model and others | Discount rate | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets   0.1962
Equity related derivative assets | Option valuation model and others | Correlation coefficient    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement   Variation of fair value increases as correlation coefficient increases.
Equity related derivative assets | Option valuation model and others | Correlation coefficient | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets   0.29
Equity related derivative assets | Option valuation model and others | Correlation coefficient | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets   0.65
Equity related derivative assets | Option valuation model and others | Stock prices, Volatility of underlying asset    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0.2255 0.2571
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as stock price and volatility increases. Variation of fair value increases as volatility and stock price increases.
Equity related derivative assets | Option valuation model and others | Liquidation value    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets 0  
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as terminal growth rate increases.  
Equity related derivative assets | Option valuation model and others | Terminal growth rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, assets   0
Impact of changes in significant unobservable inputs on fair value measurement   Fair value increases as terminal growth rate increases.
Equity securities, capital contributions, and beneficiary certificates | Stock prices, Volatility of underlying asset    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as stock price and volatility of underlying asset increases.  
Equity securities, capital contributions, and beneficiary certificates | Stock prices, Volatility of underlying asset | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.1491  
Equity securities, capital contributions, and beneficiary certificates | Stock prices, Volatility of underlying asset | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.3434  
Equity securities, capital contributions, and beneficiary certificates | LSMC(Hull-White) | Volatility    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.0056  
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as volatility increases.  
Equity securities, capital contributions, and beneficiary certificates | LSMC(Hull-White) | Discount rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as discount rate decreases. Fair value increases as discount rate decreases.
Equity securities, capital contributions, and beneficiary certificates | LSMC(Hull-White) | Discount rate | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.0383 0.0645
Equity securities, capital contributions, and beneficiary certificates | LSMC(Hull-White) | Discount rate | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.061 0.1556
Equity securities, capital contributions, and beneficiary certificates | LSMC(Hull-White) | Volatility of stock    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities   0.293
Impact of changes in significant unobservable inputs on fair value measurement   Variation of fair value increases as volatility increases.
Equity securities, capital contributions, and beneficiary certificates | Binomial Tree | Stock prices, Volatility of underlying asset    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement   Variation of fair value increases as volatility of underlying asset and stock price increases.
Equity securities, capital contributions, and beneficiary certificates | Binomial Tree | Stock prices, Volatility of underlying asset | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities   0.1876
Equity securities, capital contributions, and beneficiary certificates | Binomial Tree | Stock prices, Volatility of underlying asset | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities   0.3637
Equity securities, capital contributions, and beneficiary certificates | Binomial Tree | Volatility of stock    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as volatility of stock increases.  
Equity securities, capital contributions, and beneficiary certificates | Binomial Tree | Volatility of stock | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.2019  
Equity securities, capital contributions, and beneficiary certificates | Binomial Tree | Volatility of stock | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.3151  
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Discount rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as discount rate decreases. Fair value increases as discount rate decreases.
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Discount rate | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.0277 0.0476
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Discount rate | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.1905 0.1984
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Liquidation value    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as liquidation value increases. Fair value increases as liquidation value increases.
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Liquidation value | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities (0.01) (0.01)
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Liquidation value | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.1241 0.01
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Terminal growth rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as terminal growth rate increases. Fair value increases as terminal growth rate increases.
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Terminal growth rate | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0 0
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Terminal growth rate | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.01 0.01
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Interest rate    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Fair value increases as interest rate decreases.  
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Interest rate | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.0238  
Equity securities, capital contributions, and beneficiary certificates | DCF model and others | Interest rate | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.0342  
Equity securities, capital contributions, and beneficiary certificates | Market Value Approach | Stock price    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as stock price volatility increases.  
Equity securities, capital contributions, and beneficiary certificates | Market Value Approach | Stock price | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.2786  
Equity securities, capital contributions, and beneficiary certificates | Market Value Approach | Stock price | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.3151  
Others | Binomial Tree | Stock prices, Volatility of underlying asset    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Impact of changes in significant unobservable inputs on fair value measurement Variation of fair value increases as volatility of underlying asset and stock price increases. Variation of fair value increases as volatility of underlying asset and stock price increases.
Others | Binomial Tree | Stock prices, Volatility of underlying asset | Bottom of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.1491 0.1836
Others | Binomial Tree | Stock prices, Volatility of underlying asset | Top of range    
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Line Items]    
Significant unobservable input, liabilities 0.4244 0.369