XML 65 R52.htm IDEA: XBRL DOCUMENT v3.25.1
Electric utility segment - Public Utility, Measured under Performance (Details)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2025
USD ($)
MWh
Dec. 31, 2024
USD ($)
Regulatory Projects and Legal Obligations [Line Items]    
Interconnection requirements study PIM, estimated rewards $ 0.0  
Hawaiian Electric Company, Inc. and Subsidiaries    
Regulatory Projects and Legal Obligations [Line Items]    
Service reliability, maximum penalty 3.6  
Service reliability, estimated penalties   $ 1.0
Call center performance, pending adjusted maximum penalty 1.4  
Call center PIM, accrued estimated rewards $ 0.0  
Interpolated RPS rate goal, after year three (in dollars per MWh) | MWh 10  
Failure to meet RPS targets, penalty rate (in dollars per MWh) | MWh 20  
Accrued estimated rewards   1.9
Potential total annual maximum reward $ 3.0  
Total annual maximum penalty 0.9  
Interconnection approval PIM, accrued estimated rewards   2.4
Pending adjusted amount $ 1.0  
Accrued earned rewards, net of penalties   6.2
Hawaii Electric Light Company, Inc    
Regulatory Projects and Legal Obligations [Line Items]    
Incentives accrued   0.2
Interconnection approval PIM, accrued estimated rewards   2.8
Accrued penalties   (0.1)
Accrued earned rewards, net of penalties   3.4
Hawaiian Electric, Parent    
Regulatory Projects and Legal Obligations [Line Items]    
Public utilities retained percentage 20.00%  
Accrued earned rewards, net of penalties   $ 2.5