Name:	ifrs-full_DisclosureOfNatureAndExtentOfRisksArisingFromFinancialInstrumentsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The increase (decrease) in a financial instrument as a result of an decrease in a designated risk component that was reasonably possible at the end of the reporting period. Excludes defined benefit plan obligations.

No definition available.

Name:	sek_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleDecreaseInDesignatedRiskComponent
Namespace Prefix:	sek_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The increase (decrease) in a financial instrument as a result of an decrease in a designated risk component that was reasonably possible at the end of the reporting period measured at fair value through profit or loss.

No definition available.

Name:	sek_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleDecreaseInDesignatedRiskComponentMeasuredAtFairValueThroughProfitOrLoss
Namespace Prefix:	sek_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The increase (decrease) in a financial instrument as a result of an increase in a designated risk component that was reasonably possible at the end of the reporting period. Excludes defined benefit plan obligations.

No definition available.

Name:	sek_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleIncreaseInDesignatedRiskComponent
Namespace Prefix:	sek_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The increase (decrease) in a financial instrument as a result of an increase in a designated risk component that was reasonably possible at the end of the reporting period for instruments measured at fair value through profit or loss.

No definition available.

Name:	sek_IncreaseDecreaseInFinancialInstrumentDueToReasonablyPossibleIncreaseInDesignatedRiskComponentMeasuredAtFairValueThroughProfitOrLoss
Namespace Prefix:	sek_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The reasonably possible percentage of the decrease in the designated risk component used to determine the value of the financial instrument. Excludes defined benefit plan obligations.

No definition available.

Name:	sek_PercentageOfReasonablyPossibleDecreaseInRiskAssumption
Namespace Prefix:	sek_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

The reasonably possible percentage of the increase in the designated risk component used to determine the value of the financial instrument. Excludes defined benefit plan obligations.

No definition available.