v3.26.1
Fair Value Measurements - Summary of the Financial Assets Carried at Fair Value on a Recurring Basis (Detail) - EBP 006 [Member] - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value $ 3,750,364 $ 3,497,057
Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 950,220 465,948
Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 449,736
Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 2,800,144 2,581,373
Mutual funds [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 431,574 436,474
Mutual funds [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 431,574 436,474
Mutual funds [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Mutual funds [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Mutual funds [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 0 0
Separately managed accounts [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 308,345 296,571
Separately managed accounts [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 308,345 0
Separately managed accounts [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 296,571
Separately managed accounts [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Separately managed accounts [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 0 0
Ericsson stock fund [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 29,767 29,474
Ericsson stock fund [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 29,767 29,474
Ericsson stock fund [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Ericsson stock fund [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Ericsson stock fund [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 0 0
Commingled funds [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 1,683,583 1,570,395
Commingled funds [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Commingled funds [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Commingled funds [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Commingled funds [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 1,683,583 1,570,395
Common collective trusts [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 798,105 706,878
Common collective trusts [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Common collective trusts [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Common collective trusts [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Common collective trusts [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 798,105 706,878
Pooled separate accounts [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 318,456 304,100
Pooled separate accounts [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Pooled separate accounts [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Pooled separate accounts [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Pooled separate accounts [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] 318,456 304,100
Self-directed brokerage accounts [Member]    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 180,534 153,165
Self-directed brokerage accounts [Member] | Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 180,534 0
Self-directed brokerage accounts [Member] | Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 153,165
Self-directed brokerage accounts [Member] | Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value 0 0
Self-directed brokerage accounts [Member] | Other    
EBP, Investment, Fair Value and NAV [Line Items]    
EBP, investment, fair value [1] $ 0 $ 0
[1] As these assets are measured at net asset value using the practical expedient they are therefore excluded from the fair value hierarchy and included in other.