v3.24.3
Electric utility segment - Annual Decoupling Filings Summary (Details) - USD ($)
$ in Millions
 9 Months Ended
Oct. 28, 2024
Sep. 30, 2024
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues   $ 22.9
Annual change in accrued RBA balance through September 30, 2024 (and associated revenue taxes)   (1.9)
Incremental PIMs (net)   0.0
Net incremental amount to be collected under the RBA rate tariffs   21.0
Subsequent Event    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues $ 22.9  
Management Audit savings commitment (6.6)  
Net 2025 ARA revenues 16.3  
Hawaiian Electric, Parent    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues   15.4
Annual change in accrued RBA balance through September 30, 2024 (and associated revenue taxes)   (7.0)
Incremental PIMs (net)   (0.1)
Net incremental amount to be collected under the RBA rate tariffs   8.3
Hawaiian Electric, Parent | Subsequent Event    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues 15.4  
Management Audit savings commitment (4.6)  
Net 2025 ARA revenues 10.8  
Hawaii Electric Light    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues   3.8
Annual change in accrued RBA balance through September 30, 2024 (and associated revenue taxes)   (1.3)
Incremental PIMs (net)   0.1
Net incremental amount to be collected under the RBA rate tariffs   2.6
Hawaii Electric Light | Subsequent Event    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues 3.8  
Management Audit savings commitment (1.0)  
Net 2025 ARA revenues 2.8  
Maui Electric    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues   3.7
Annual change in accrued RBA balance through September 30, 2024 (and associated revenue taxes)   6.4
Incremental PIMs (net)   0.0
Net incremental amount to be collected under the RBA rate tariffs   $ 10.1
Maui Electric | Subsequent Event    
Regulatory Projects and Legal Obligations [Line Items]    
2025 ARA revenues 3.7  
Management Audit savings commitment (1.0)  
Net 2025 ARA revenues $ 2.7