Financial Risk Management - Disclosure of Outstanding Derivatives (Detail) - SEK (kr) kr in Millions	Dec. 31, 2024	Dec. 31, 2023
Currency Derivatives [member] \| Liabilities [member]
Outstanding Derivatives [Line Items]
Outstanding derivatives gross amount recognized	kr (3,361)	kr (1,837)
Outstanding derivatives offset	29	43
Outstanding derivatives net amount presented	(3,332)	(1,794)
Outstanding derivatives related amounts not offset – Collaterals	3,237	873
Net Outstanding derivatives	(95)	(921)
Currency Derivatives [member] \| Assets [member]
Outstanding Derivatives [Line Items]
Outstanding derivatives gross amount recognized	214	1,916
Outstanding derivatives offset	(29)	(43)
Outstanding derivatives net amount presented	185	1,873
Outstanding derivatives related amounts not offset – Collaterals	(92)	(1,486)
Net Outstanding derivatives	93	387
Interest Rate Derivatives [member] \| Liabilities [member]
Outstanding Derivatives [Line Items]
Outstanding derivatives gross amount recognized	(5)	(22)
Outstanding derivatives offset	0	0
Outstanding derivatives net amount presented	(5)	(22)
Outstanding derivatives related amounts not offset – Collaterals	0	0
Net Outstanding derivatives	(5)	(22)
Interest Rate Derivatives [member] \| Assets [member]
Outstanding Derivatives [Line Items]
Outstanding derivatives gross amount recognized	0	0
Outstanding derivatives offset	0	0
Outstanding derivatives net amount presented	0	0
Outstanding derivatives related amounts not offset – Collaterals	0	0
Net Outstanding derivatives	kr 0	kr 0

Outstanding derivatives Line items.

No definition available.

Name:	eric_OutstandingDerivativesLineItems
Namespace Prefix:	eric_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of cash collateral pledged that is subject to an enforceable master netting arrangement or similar agreement and that is not set off against financial liabilities. [Refer: Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph IG40D
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_IG40D&doctype=Implementation%20Guidance
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 13C
-Subparagraph d
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_13C_d_ii&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_CashCollateralPledgedSubjectToEnforceableMasterNettingArrangementOrSimilarAgreementNotSetOffAgainstFinancialLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of cash collateral received that is subject to an enforceable master netting arrangement or similar agreement and that is not set off against financial assets. [Refer: Financial assets]

+ References

+ Details

Name:	ifrs-full_CashCollateralReceivedSubjectToEnforceableMasterNettingArrangementOrSimilarAgreementNotSetOffAgainstFinancialAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of financial assets set off against financial liabilities when an entity: (a) currently has a legally enforceable right to set off the recognised amounts; and (b) intends either to settle on a net basis, or to realise the asset and settle the liability simultaneously. [Refer: Financial assets; Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 13C
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_13C_b&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_GrossFinancialAssetsSetOffAgainstFinancialLiabilitiesSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The gross amount of recognised financial assets that are subject either to offsetting or to an enforceable master netting arrangement or similar agreement. [Refer: Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 13C
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_13C_a&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_GrossFinancialAssetsSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of financial liabilities set off against financial assets when an entity: (a) currently has a legally enforceable right to set off the recognised amounts; and (b) intends either to settle on a net basis or to realise the asset and settle the liability simultaneously. [Refer: Financial assets; Financial liabilities]

+ References

+ Details

Name:	ifrs-full_GrossFinancialLiabilitiesSetOffAgainstFinancialAssetsSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The gross amount of recognised financial liabilities that are subject either to offsetting or to an enforceable master netting arrangement or similar agreement. [Refer: Financial liabilities]

+ References

+ Details

Name:	ifrs-full_GrossFinancialLiabilitiesSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount remaining after deducting the amounts subject to an enforceable master netting arrangement or similar agreement that were not set off against financial assets, from the net amount of financial assets subject to offsetting or subject to an enforceable master netting arrangement or similar agreement presented in the statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 13C
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_13C_e&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_NetFinancialAssetsSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The net amount of financial assets that are subject either to offsetting or to an enforceable master netting arrangement or similar agreement, presented in the statement of financial position. [Refer: Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 13C
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_13C_c&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_NetFinancialAssetsSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreementsInStatementOfFinancialPosition
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount remaining after deducting the amounts subject to an enforceable master netting arrangement or similar agreement that were not set off against financial liabilities, from the net amount of financial liabilities subject to offsetting or subject to an enforceable master netting arrangement or similar agreement presented in the statement of financial position.

+ References

+ Details

Name:	ifrs-full_NetFinancialLiabilitiesSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The net amount of financial liabilities that are subject either to offsetting or to an enforceable master netting arrangement or similar agreement, presented in the statement of financial position. [Refer: Financial liabilities]

+ References

+ Details

Name:	ifrs-full_NetFinancialLiabilitiesSubjectToOffsettingEnforceableMasterNettingArrangementsOrSimilarAgreementsInStatementOfFinancialPosition
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=eric_CurrencyDerivativesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=ifrs-full_ClassesOfLiabilitiesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_ClassesOfAssetsDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=eric_InterestRateDerivativesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: