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Electric utility segment - HECO Capital Trust III (Details) - VIE, Not Primary Beneficiary - USD ($) $ in Thousands | 9 Months Ended |
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017
Variable Interest Entity [Line Items] |  |  |
Investments | $ 51,500 |  | $ 51,500
Investment income, interest | 2,500 | $ 2,500 |
Trust Preferred Securities Subject to Mandatory Redemption | Hawaiian Electric Company |  |  |
Variable Interest Entity [Line Items] |  |  |
Convertible preferred stock | 50,000 |  | 50,000
Distributions to holders of Trust Preferred Securities | 2,400 | 2,400 |
Trust Common Securities | Hawaiian Electric Company |  |  |
Variable Interest Entity [Line Items] |  |  |
Convertible preferred stock | 1,500 |  | $ 1,500
Common dividends on the trust common securities | $ 75 | $ 75 |

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- Definition Preferred securities that embody an unconditional obligation requiring the issuer to redeem the securities by transferring the assets at a specified or determinable date (or dates) or upon an event that is certain to occur, that are issued by a trust to outside investors where the trust uses the proceeds of the issuance of those securities to purchase an equivalent amount of junior subordinated debentures or other loans having stated maturities. + References No definition available. + Details
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- Definition Adjustment to net income reflecting the dividends paid to the holders of Trust Common Securities. + References No definition available. + Details
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- Definition The amount of interest incurred to a trust which has issued trust-preferred securities. In order to issue trust preferred securities, a sponsor forms a trust by investing a nominal amount of cash to purchase all of the voting common stock of the trust. The trust issues nonvoting, mandatorily redeemable preferred securities to outside investors in exchange for cash. The proceeds received from the issuance of the preferred securities, together with the cash received for issuing the common stock to the sponsor, is then loaned to the sponsor in exchange for a note which has the same terms as the trust preferred securities. Trust preferred securities possesses characteristics of both equity and debt issues and are generally issued by bank holding companies. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(9)) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 + Details
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