| Document | Jul. 22, 2019 |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Jul. 22, 2019 |
| Entity Registrant Name | BANK OF HAWAII CORP |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-6887 |
| Entity Tax Identification Number | 99-0148992 |
| Entity Address, Address Line One | 130 Merchant Street |
| Entity Address, City or Town | Honolulu |
| Entity Address, State or Province | HI |
| Entity Address, Postal Zip Code | 96813 |
| City Area Code | (888) |
| Local Phone Number | 643-3888 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0000046195 |
| NEW YORK STOCK EXCHANGE, INC. [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | BOH |
| Security Exchange Name | NYSE |
