v3.25.4
Risk information - Liquidity reserve (Details) - Liquidity risk - SEK (kr)
kr in Billions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Maturity term of borrowing programs used to secure access to short-term borrowing 1 year  
Period of monitoring the liquidity coverage ratio 30 days  
Liquidity reserve kr 57.2 kr 57.7
Skr    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 22.4 32.2
EUR    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 12.7 11.8
USD    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 22.1 13.7
Other    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 0.0 0.0
Securities issued or guaranteed by sovereigns, central banks or multilateral development banks    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 33.0 25.3
Securities issued or guaranteed by sovereigns, central banks or multilateral development banks | Skr    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 6.0 11.0
Securities issued or guaranteed by sovereigns, central banks or multilateral development banks | EUR    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 11.2 8.0
Securities issued or guaranteed by sovereigns, central banks or multilateral development banks | USD    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 15.8 6.3
Securities issued or guaranteed by municipalities or other public entities    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 11.2 18.3
Securities issued or guaranteed by municipalities or other public entities | Skr    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 4.2 7.1
Securities issued or guaranteed by municipalities or other public entities | EUR    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 0.7 3.8
Securities issued or guaranteed by municipalities or other public entities | USD    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 6.3 7.4
Covered bonds issued by other institutions    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 12.0 13.1
Covered bonds issued by other institutions | Skr    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 11.2 13.1
Covered bonds issued by other institutions | EUR    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 0.8  
Balances with National Debt Office    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve 1.0 1.0
Balances with National Debt Office | Skr    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Liquidity reserve kr 1.0 kr 1.0