Hawaiian Electric Company, Inc. Hawaiian Electric Company, Inc. [Member] Hawaiian Electric Company, Inc. [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Address, City or Town Entity Address, City or Town Entities [Table] Entities [Table] Soliciting Material Soliciting Material Entity Address, Address Line One Entity Address, Address Line One Security Exchange Name Security Exchange Name City Area Code City Area Code Cover page. Cover [Abstract] Entity Central Index Key Entity Central Index Key Entity Tax Identification Number Entity Tax Identification Number Entity File Number Entity File Number Document Type Document Type Entity Emerging Growth Company Entity Emerging Growth Company Title of each class Title of 12(b) Security Amendment Flag Amendment Flag Entity Address, State or Province Entity Address, State or Province Trading Symbol Trading Symbol Document Period End Date Document Period End Date Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Written Communications Written Communications Pre-commencement Tender Offer Pre-commencement Tender Offer Legal Entity [Axis] Legal Entity [Axis] Local Phone Number Local Phone Number Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity [Domain] Entity [Domain] Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer