v3.25.2
Financial assets and liabilities at fair value - Assets and liabilities Sensitivity analysis - level 3 (Details)
kr in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2025
SEK (kr)
Dec. 31, 2024
SEK (kr)
Dec. 31, 2023
SEK (kr)
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity, correlations maximum positive relationship 1    
Sensitivity correlations maximum negative relationship (1)    
Financial liabilities at fair value kr (340,161) kr (330,209)  
Correlation input      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity, input appreciation, assets 0.12    
Sensitivity, input depreciation, assets 0.12    
Sensitivity, input appreciation, liabilities 0.12    
Sensitivity, input depreciation, liabilities 0.12    
Credit spread input      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity, input appreciation, assets 0.10%    
Sensitivity, input depreciation, assets 0.10%    
Sensitivity, input appreciation, liabilities 0.10%    
Sensitivity, input depreciation, liabilities 0.10%    
Level 3      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Net assets (liabilities) kr (3,981) (4,903) kr (10,550)
Level 3 | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity impact on total comprehensive income 14 16  
Level 3 | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity impact on total comprehensive income (14) (16)  
Level 3 | Derivatives      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Net assets (liabilities) (991) (1,451) (2,279)
Level 3 | Derivatives | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity impact on total comprehensive income (19) (18)  
Level 3 | Derivatives | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity impact on total comprehensive income 19 18  
Level 3 | Derivatives | Equity risk      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Net assets (liabilities) kr 0    
Level 3 | Derivatives | Equity risk | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Derivatives | Equity risk | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Derivatives | Interest rate      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Net assets (liabilities) kr 0    
Level 3 | Derivatives | Interest rate | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Derivatives | Interest rate | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Derivatives | Currency risk      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Net assets (liabilities) kr (884)    
Level 3 | Derivatives | Currency risk | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr (19)    
Level 3 | Derivatives | Currency risk | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 19    
Level 3 | Derivatives | Other      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Net assets (liabilities) kr (107)    
Level 3 | Derivatives | Other | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Derivatives | Other | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Financial liabilities at fair value (2,990) (3,452) kr (8,271)
Level 3 | Debt securities issued | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity impact on total comprehensive income 33 34  
Level 3 | Debt securities issued | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Sensitivity impact on total comprehensive income (33) kr (34)  
Level 3 | Debt securities issued | Equity risk      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Financial liabilities at fair value kr 0    
Level 3 | Debt securities issued | Equity risk | Discounted cash flow | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) 10    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Equity risk | Discounted cash flow | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) (10)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Equity risk | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Equity risk | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Interest rate      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Financial liabilities at fair value kr 0    
Level 3 | Debt securities issued | Interest rate | Discounted cash flow | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) 10    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Interest rate | Discounted cash flow | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) (10)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Interest rate | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Interest rate | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Currency risk      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Financial liabilities at fair value kr (2,889)    
Level 3 | Debt securities issued | Currency risk | Discounted cash flow | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) 10    
Sensitivity impact on total comprehensive income kr 14    
Level 3 | Debt securities issued | Currency risk | Discounted cash flow | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) (10)    
Sensitivity impact on total comprehensive income kr (14)    
Level 3 | Debt securities issued | Currency risk | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 19    
Level 3 | Debt securities issued | Currency risk | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr (19)    
Level 3 | Debt securities issued | Other      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Financial liabilities at fair value kr (101)    
Level 3 | Debt securities issued | Other | Discounted cash flow | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) 10    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Other | Discounted cash flow | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Credit spreads (in basis points) (10)    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Other | Option Model | Maximum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation 0.12    
Sensitivity impact on total comprehensive income kr 0    
Level 3 | Debt securities issued | Other | Option Model | Minimum      
Disclosure of significant unobservable inputs used in fair value measurement of assets      
Correlation (0.12)    
Sensitivity impact on total comprehensive income kr 0