XML 82 R65.htm IDEA: XBRL DOCUMENT v3.10.0.1
Credit agreements and long-term debt (Details)
1 Months Ended
Jun. 30, 2018
USD ($)
Institution
May 30, 2018
USD ($)
Dec. 31, 2017
USD ($)
Debt Disclosure [Abstract]      
Number of financial institutions | Institution 8    
Line of credit facility      
Credit agreement      
Revolving noncollateralized credit facility with a letter of credit sub-facility $ 150,000,000    
Amount outstanding under facilities 0   $ 0
Line of credit facility | Hawaiian Electric Company      
Credit agreement      
Revolving noncollateralized credit facility with a letter of credit sub-facility 200,000,000    
Amount outstanding under facilities 0   $ 0
Unsecured Debt | Mauo, LLC      
Credit agreement      
Aggregate principal amount 0    
Debt, face amount $ 50,500,000    
Unsecured Debt | Mauo, LLC | London Interbank Offered Rate (LIBOR)      
Credit agreement      
Basis spread on variable rate 1.375%    
Unsecured Debt | Series 2018A      
Credit agreement      
Aggregate principal amount   $ 67,500,000  
Fixed coupon interest rate   4.38%  
Unsecured Debt | Series 2018A | Hawaiian Electric Company, Inc. and Subsidiaries      
Credit agreement      
Aggregate principal amount   $ 52,000,000  
Unsecured Debt | Series 2018A | Hawaii Electric Light Company, Inc. (HELCO)      
Credit agreement      
Aggregate principal amount   9,000,000  
Unsecured Debt | Series 2018A | Maui Electric      
Credit agreement      
Aggregate principal amount   6,500,000  
Unsecured Debt | Series 2018B      
Credit agreement      
Aggregate principal amount   $ 17,500,000  
Fixed coupon interest rate   4.53%  
Unsecured Debt | Series 2018B | Hawaiian Electric Company, Inc. and Subsidiaries      
Credit agreement      
Aggregate principal amount   $ 12,500,000  
Unsecured Debt | Series 2018B | Hawaii Electric Light Company, Inc. (HELCO)      
Credit agreement      
Aggregate principal amount   3,000,000  
Unsecured Debt | Series 2018B | Maui Electric      
Credit agreement      
Aggregate principal amount   2,000,000  
Unsecured Debt | Series 2018C      
Credit agreement      
Aggregate principal amount   $ 15,000,000  
Fixed coupon interest rate   4.72%  
Unsecured Debt | Series 2018C | Hawaiian Electric Company, Inc. and Subsidiaries      
Credit agreement      
Aggregate principal amount   $ 10,500,000  
Unsecured Debt | Series 2018C | Hawaii Electric Light Company, Inc. (HELCO)      
Credit agreement      
Aggregate principal amount   3,000,000  
Unsecured Debt | Series 2018C | Maui Electric      
Credit agreement      
Aggregate principal amount   $ 1,500,000