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Credit agreements and changes in debt - Note Purchase Agreements (Details) - Senior Notes | May 14, 2020 USD ($)
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Unsecured Senior Notes Series 2020A |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 80,000,000
Unsecured Senior Notes Series 2020A | Hawaiian Electric (parent only) |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 50,000,000
Fixed coupon interest rate | 3.31%
Unsecured Senior Notes Series 2020A | HELCO |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 10,000,000
Fixed coupon interest rate | 3.96%
Unsecured Senior Notes Series 2020A | Maui Electric |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 20,000,000
Fixed coupon interest rate | 3.31%
Unsecured Senior Notes Series 2020B |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 60,000,000
Unsecured Senior Notes Series 2020B | Hawaiian Electric (parent only) |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 40,000,000
Fixed coupon interest rate | 3.31%
Unsecured Senior Notes Series 2020B | Maui Electric |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 20,000,000
Fixed coupon interest rate | 3.96%
Unsecured Senior Notes Series 2020C |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 20,000,000
Unsecured Senior Notes Series 2020C | Hawaiian Electric (parent only) |
Debt Instrument [Line Items] |
Aggregate principal amount | $ 20,000,000
Fixed coupon interest rate | 3.96%

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