v3.26.1
Shareholders' equity - Schedule of Reclassification out of AOCI (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Reclassifications out of accumulated other comprehensive income/(loss)        
Interest expense, net (Note 2) $ (48,383) $ (27,256) $ (79,511) $ (61,468)
Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications (75) (74) (149) (146)
Hawaiian Electric Company, Inc. and Subsidiaries        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications (137,858) (39,649) (173,201) (87,964)
Hawaiian Electric Company, Inc. and Subsidiaries | Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications (47) (47) (94) (94)
Net realized gains on derivatives qualifying as cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Interest expense, net (Note 2) (54) (50) (106) (100)
Amortization of net gains recognized during the period in net periodic benefit cost | Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications (457) (508) (915) (1,013)
Amortization of net gains recognized during the period in net periodic benefit cost | Hawaiian Electric Company, Inc. and Subsidiaries | Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications (483) (531) (966) (1,061)
Impact of D&Os of the PUC included in regulatory accounts | Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications 436 484 872 967
Impact of D&Os of the PUC included in regulatory accounts | Hawaiian Electric Company, Inc. and Subsidiaries | Reclassification out of Accumulated Other Comprehensive Income        
Reclassifications out of accumulated other comprehensive income/(loss)        
Total reclassifications $ 436 $ 484 $ 872 $ 967