Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Bank of Hawaii Corporation (the “Parent”) is a Delaware corporation and a bank holding company headquartered in Honolulu, Hawaii. Bank of Hawai‘i Corporation is a trade name of Bank of Hawaii Corporation, and along with its subsidiaries (collectively, the “Company”), provides a broad range of financial products and services to businesses, consumers and governments in Hawaii and the West Pacific. The majority of the Company’s operations consist of customary commercial and consumer banking services including, but not limited to, lending, leasing, deposit services, trust and investment activities, brokerage services, and trade financing. The accompanying consolidated financial statements include the accounts of the Parent and its subsidiaries. The Parent’s principal operating subsidiary is Bank of Hawaii (the “Bank”), doing business as Bank of Hawai‘i. The consolidated financial statements in this report have not been audited by an independent registered public accounting firm, but, in the opinion of management, reflect all adjustments necessary for a fair presentation of the results for the interim periods. All such adjustments are of a normal recurring nature. Intercompany accounts and transactions have been eliminated in consolidation. Certain prior period information has been reclassified to conform to the current period presentation. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for the full fiscal year or any future period. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and accompanying notes required by GAAP for complete financial statements and should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. Significant changes to accounting policies from those disclosed in our audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K are presented below. In January 2023, the Company adopted ASU 2022-02, “Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures” (“ASU 2022-02”), which eliminated the accounting guidance for troubled debt restructurings (“TDRs”) while enhancing disclosure requirements for certain loan refinancing and restructurings by creditors when a borrower is experiencing financial difficulty. This guidance was applied on a prospective basis. Upon adoption of this guidance, the Company no longer establishes a specific reserve for modifications made on January 1, 2023 and forward to borrowers experiencing financial difficulty. Instead, these modifications are included in their respective cohort and a historical loss rate is applied to the current loan balance to arrive at the quantitative baseline portion of the Allowance for Credit Losses. Modifications to borrowers experiencing financial difficulty may include interest rate reductions, principal or interest forgiveness, forbearances, term extensions, and other actions intended to minimize economic loss and to avoid foreclosure or repossession of collateral.
Accounting Standard Pending Adoption	Accounting Standard Pending Adoption In March 2023, the FASB issued ASU 2023-02, “Investments – Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Tax Credit Structures Using the Proportional Amortization Method.” ASU 2023-02 permits reporting entities to elect to account for their tax equity investments, regardless of the tax credit program from which the income tax credits are received, using the proportional amortization method if certain conditions are met. ASU 2023-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2023. ASU 2023-02 is not expected to have a material impact on the Company’s consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2023

Bank of Hawaii Corporation (the “Parent”) is a Delaware corporation and a bank holding company headquartered in Honolulu, Hawaii. Bank of Hawai‘i Corporation is a trade name of Bank of Hawaii Corporation, and along with its subsidiaries (collectively, the “Company”), provides a broad range of financial products and services to businesses, consumers and governments in Hawaii and the West Pacific. The majority of the Company’s operations consist of customary commercial and consumer banking services including, but not limited to, lending, leasing, deposit services, trust and investment activities, brokerage services, and trade financing. The accompanying consolidated financial statements include the accounts of the Parent and its subsidiaries. The Parent’s principal operating subsidiary is Bank of Hawaii (the “Bank”), doing business as Bank of Hawai‘i.

The consolidated financial statements in this report have not been audited by an independent registered public accounting firm, but, in the opinion of management, reflect all adjustments necessary for a fair presentation of the results for the interim periods. All such adjustments are of a normal recurring nature. Intercompany accounts and transactions have been eliminated in consolidation. Certain prior period information has been reclassified to conform to the current period presentation. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for the full fiscal year or any future period.

The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and accompanying notes required by GAAP for complete financial statements and should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. Significant changes to accounting policies from those disclosed in our audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K are presented below.

In January 2023, the Company adopted ASU 2022-02, “Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures” (“ASU 2022-02”), which eliminated the accounting guidance for troubled debt restructurings (“TDRs”) while enhancing disclosure requirements for certain loan refinancing and restructurings by creditors when a borrower is experiencing financial difficulty. This guidance was applied on a prospective basis. Upon adoption of this guidance, the Company no longer establishes a specific reserve for modifications made on January 1, 2023 and forward to borrowers experiencing financial difficulty. Instead, these modifications are included in their respective cohort and a historical loss rate is applied to the current loan balance to arrive at the quantitative baseline portion of the Allowance for Credit Losses.

Modifications to borrowers experiencing financial difficulty may include interest rate reductions, principal or interest forgiveness, forbearances, term extensions, and other actions intended to minimize economic loss and to avoid foreclosure or repossession of collateral.

Accounting Standard Pending Adoption

In March 2023, the FASB issued ASU 2023-02, “Investments – Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Tax Credit Structures Using the Proportional Amortization Method.” ASU 2023-02 permits reporting entities to elect to account for their tax equity investments, regardless of the tax credit program from which the income tax credits are received, using the proportional amortization method if certain conditions are met. ASU 2023-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2023. ASU 2023-02 is not expected to have a material impact on the Company’s consolidated financial statements.