v3.26.1
Financial assets and liabilities at fair value - Financial assets & liabilities reported at fair value in fair value hierarchy (Details) - SEK (kr)
kr in Millions
Jun. 30, 2026
Dec. 31, 2025
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets kr 358,433 kr 343,254
Fair value of financial liabilities 322,449 314,304
Debt securities issued    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 313,381 300,906
Derivatives    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 3,816 8,988
Financial liabilities at fair value through profit or loss, category    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 21,982 25,848
Financial liabilities at fair value through profit or loss, category | Level 1    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 0 0
Financial liabilities at fair value through profit or loss, category | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 20,367 22,186
Financial liabilities at fair value through profit or loss, category | Level 3    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 1,614 3,662
Financial liabilities at fair value through profit or loss, category | Debt securities issued    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 18,166  
Financial liabilities at fair value through profit or loss, category | Debt securities issued | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 17,129  
Financial liabilities at fair value through profit or loss, category | Debt securities issued | Level 3    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 1,037  
Financial liabilities at fair value through profit or loss, category | Derivatives    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 3,816  
Financial liabilities at fair value through profit or loss, category | Derivatives | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 3,239  
Financial liabilities at fair value through profit or loss, category | Derivatives | Level 3    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial liabilities 577  
Financial assets at fair value through profit or loss, category    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 73,523 63,377
Financial assets at fair value through profit or loss, category | Level 1    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 24,387 22,215
Financial assets at fair value through profit or loss, category | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 49,135 41,161
Financial assets at fair value through profit or loss, category | Level 3    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 1 1
Treasuries/governments bonds    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 12,047 13,419
Treasuries/governments bonds | Financial assets at fair value through profit or loss, category    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 12,047  
Treasuries/governments bonds | Financial assets at fair value through profit or loss, category | Level 1    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 1,059  
Treasuries/governments bonds | Financial assets at fair value through profit or loss, category | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 10,988  
Other interest-bearing securities except loans    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 54,268 43,237
Other interest-bearing securities except loans | Financial assets at fair value through profit or loss, category    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 54,268  
Other interest-bearing securities except loans | Financial assets at fair value through profit or loss, category | Level 1    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 23,328  
Other interest-bearing securities except loans | Financial assets at fair value through profit or loss, category | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 30,940  
Derivatives    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 7,208 kr 6,721
Derivatives | Financial assets at fair value through profit or loss, category    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 7,208  
Derivatives | Financial assets at fair value through profit or loss, category | Level 2    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets 7,207  
Derivatives | Financial assets at fair value through profit or loss, category | Level 3    
Disclosure of detailed information about financial instruments [line items]    
Fair value of financial assets kr 1