| Cover | Jan. 15, 2021 | Oct. 22, 2020 |
| Entity Information [Line Items] | ||
| Document Type | 8-K | |
| Entity Registrant Name | Hawaiian Electric Industries, Inc. | |
| Entity File Number | 1-8503 | |
| Entity Tax Identification Number | 99-0208097 | |
| Entity Incorporation, State or Country Code | HI | |
| Entity Address, Address Line One | 1001 Bishop Street, Suite 2900 | |
| Entity Address, City or Town | Honolulu | |
| Entity Address, State or Province | HI | |
| Entity Address, Postal Zip Code | 96813 | |
| City Area Code | 808 | |
| Local Phone Number | 543-5662 | |
| Written Communications | false | |
| Soliciting Material | false | |
| Pre-commencement Tender Offer | false | |
| Pre-commencement Issuer Tender Offer | false | |
| Title of each class | Common Stock, Without Par Value | |
| Trading Symbol | HE | |
| Security Exchange Name | NYSE | |
| Entity Emerging Growth Company | false | |
| Entity Central Index Key | 0000354707 | |
| Amendment Flag | false | |
| Document Period End Date | Jan. 15, 2021 | |
| Hawaiian Electric Company, Inc. | ||
| Entity Information [Line Items] | ||
| Entity Registrant Name | Hawaiian Electric Company, Inc. | |
| Entity File Number | 1-4955 | |
| Entity Tax Identification Number | 99-0040500 | |
| Entity Address, Address Line One | 1001 Bishop Street, Suite 2500 | |
| Entity Address, City or Town | Honolulu | |
| Entity Address, State or Province | HI | |
| Entity Address, Postal Zip Code | 96813 | |
| City Area Code | 808 | |
| Local Phone Number | 543-7771 | |
| Entity Emerging Growth Company | false | |
| Entity Central Index Key | 0000046207 | |
| Amendment Flag | false |
