v3.26.1
Electric utility segment - Schedule of Purchases from IPPs (Details) - Hawaiian Electric - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power $ 224 $ 175 $ 369 $ 322
Kalaeloa Partners, L.P.        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 113 69 170 128
HPOWER        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 18 20 31 39
Hamakua Energy        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 18 8 30 13
Puna Geothermal Venture        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 10 6 19 19
Kapolei Energy Storage        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 6 6 12 12
Solar IPPs        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 30 29 57 51
Wind IPPs        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power 28 36 48 57
Other IPPs        
Regulatory Projects and Legal Obligations [Line Items]        
Purchased power $ 1 $ 1 $ 2 $ 3