Document and Entity Information
| Document and Entity Information | Jun. 14, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | BANK OF HAWAII CORP |
| Amendment Flag | false |
| Entity Central Index Key | 0000046195 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Jun. 14, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-6887 |
| 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 |
| Security 12b Title | Common Stock, $0.01 Par Value |
| Trading Symbol | BOH |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |