Amount of increase in other non interest expense.

No definition available.

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- Definition

Amount of proceeds expected to be received from a tax settlement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Unused amount of credit commitments to customers sold as a participation to one or more lenders.

+ References

No definition available.

+ Details

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Namespace Prefix:	fhb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-9

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- Details

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Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Commitments and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended
	Jul. 31, 2026	Jun. 30, 2026	Dec. 31, 2025
Subsequent event
Commitments and Contingent Liabilities
Amount of proceeds expected to be received from a tax settlement	$ 90.2
Increase in other non interest expense	24.3
Decrease in provision for income taxes	$ (31.0)
Commitments to extend credit
Commitments and Contingent Liabilities
Participations sold to other institutions		$ 42.2	$ 86.4
Standby letters of credit
Commitments and Contingent Liabilities
Participations sold to other institutions		$ 6.3	$ 6.3