v3.26.1
Retirement benefits - Schedule of Components of Net Periodic Benefit Cost for Consolidated HEI (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension benefits        
Defined Benefit Plan        
Service cost $ 9,838 $ 9,948 $ 19,676 $ 19,896
Interest cost 27,564 26,304 55,128 52,609
Expected return on plan assets (33,832) (33,856) (67,664) (67,713)
Amortization of net actuarial (gain)/losses 65 65 131 130
Net periodic pension/benefit cost (return) 3,635 2,461 7,271 4,922
Impact of PUC D&Os 16,619 17,800 33,236 35,599
Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os) 20,254 20,261 40,507 40,521
Other benefits        
Defined Benefit Plan        
Service cost 245 248 491 496
Interest cost 1,778 1,821 3,557 3,642
Expected return on plan assets (3,590) (3,510) (7,182) (7,020)
Amortization of net actuarial (gain)/losses (682) (746) (1,364) (1,492)
Net periodic pension/benefit cost (return) (2,249) (2,187) (4,498) (4,374)
Impact of PUC D&Os 2,082 2,024 4,166 4,049
Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os) (167) (163) (332) (325)
Hawaiian Electric Company, Inc. and Subsidiaries | Pension benefits        
Defined Benefit Plan        
Service cost 9,650 9,705 19,300 19,410
Interest cost 26,667 25,430 53,333 50,859
Expected return on plan assets (33,039) (33,052) (66,077) (66,101)
Amortization of net actuarial (gain)/losses 24 24 49 47
Net periodic pension/benefit cost (return) 3,302 2,107 6,605 4,215
Impact of PUC D&Os 16,619 17,800 33,236 35,599
Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os) 19,921 19,907 39,841 39,814
Hawaiian Electric Company, Inc. and Subsidiaries | Other benefits        
Defined Benefit Plan        
Service cost 242 245 485 490
Interest cost 1,699 1,740 3,398 3,481
Expected return on plan assets (3,542) (3,461) (7,087) (6,923)
Amortization of net actuarial (gain)/losses (676) (737) (1,351) (1,474)
Net periodic pension/benefit cost (return) (2,277) (2,213) (4,555) (4,426)
Impact of PUC D&Os 2,082 2,024 4,166 4,049
Net periodic pension/benefit cost (return) (adjusted for impact of PUC D&Os) $ (195) $ (189) $ (389) $ (377)