Cover page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 20, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	1-6887
Entity Registrant Name	BANK OF HAWAII CORP
Entity Incorporation, State or Country Code	DE
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
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		40,245,113
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000046195
Current Fiscal Year End Date	--12-31
Amendment Flag	false
NEW YORK STOCK EXCHANGE, INC. [Member] | Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	BOH
Security Exchange Name	NYSE
NEW YORK STOCK EXCHANGE, INC. [Member] | Series A Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	Depository Shares, Each Representing 1/40th Interest in a Share of 4.375% Fixed Rate Non-Cumulative Preferred Stock, Series A
Trading Symbol	BOH.PRA
Security Exchange Name	NYSE