Number of interest rate derivative instruments executed by the entity during the period.

No definition available.

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- Definition

Represents the number of interest rate swaps held by the entity at the reporting date.

+ References

No definition available.

+ Details

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- Definition

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5

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Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

+ Details

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Period Type:	instant

- Definition

Floor rate on an interest rate derivative such as an interest rate floor or collar. If market rates falls below the floor rate, a payment or receipt is triggered on the contract.

+ References

+ Details

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Period Type:	instant

- Definition

Estimated period for anticipated transfer of gain (loss) from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-1

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Data Type:	xbrli:durationItemType
Balance Type:	na
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- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

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- Definition

Amount of premium paid on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 320
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SX 210.12-13(Column A)(Footnote 3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 5C
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-SubTopic 320
-Topic 946
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5C

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 5C
-Subparagraph (SX 210.12-13C(Column H)(Footnote 7))
-SubTopic 320
-Topic 946
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5C

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5A

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- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

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Derivative Financial Instruments - Fair Value Hedges and Cash Flow Hedges (Details) $ in Thousands	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2026 USD ($) derivative	Mar. 31, 2026 derivative	Jun. 30, 2026 USD ($) derivative	Dec. 31, 2025 USD ($) derivative
Location, Statement of Other Comprehensive Income, Balance [Axis]: fhb:FsTypedDimensionConstraint2Member
Fair hedges carried
AOCI into earnings			$ 2,200
Hedge term			3 years
Designated as hedging instruments \| Cash Flow Hedging
Fair hedges carried
Number of interest rate derivatives executed \| derivative		3	6
Notional amounts	$ 600,000		$ 600,000
Total paid premiums	3,800		3,800
Designated as hedging instruments \| Interest rate swaps
Fair hedges carried
Notional amounts	58,125		$ 58,125	$ 60,000
Designated as hedging instruments \| Interest rate swaps \| Fair Value Hedging
Fair hedges carried
Number of interest rate swaps \| derivative			1	1
Notional amounts	58,100		$ 58,100	$ 60,000
Positive fair value	$ 8,500		$ 8,500	7,500
Fixed interest rates (as a percent)	2.07%		2.07%
Designated as hedging instruments \| Interest rate collars
Fair hedges carried
Notional amounts	$ 100,000		$ 100,000	$ 100,000
Designated as hedging instruments \| Interest rate collars \| Cash Flow Hedging
Fair hedges carried
Number of derivatives carried \| derivative	1		1	1
Notional amounts	$ 100,000		$ 100,000	$ 100,000
Positive fair value	$ 0		$ 0	100
Floor strike rate	2.00%		2.00%
Cap strike rates	5.64%		5.64%
Designated as hedging instruments \| Interest rate floors
Fair hedges carried
Notional amounts	$ 900,000		$ 900,000	$ 300,000
Designated as hedging instruments \| Interest rate floors \| Cash Flow Hedging
Fair hedges carried
Number of derivatives carried \| derivative	9		9
Notional amounts	$ 900,000		$ 900,000
Positive fair value	$ 3,100		3,100
Designated as hedging instruments \| Mature in 2028 \| Cash Flow Hedging
Fair hedges carried
Number of derivatives carried \| derivative				3
Notional amounts				$ 300,000
Positive fair value				1,700
Total paid premiums				$ 2,900
Designated as hedging instruments \| Mature in 2028 \| Cash Flow Hedging \| Minimum
Fair hedges carried
Floor strike rate				2.95%
Designated as hedging instruments \| Mature in 2028 \| Cash Flow Hedging \| Maximum
Fair hedges carried
Floor strike rate				3.00%
Designated as hedging instruments \| Mature in 2029 \| Cash Flow Hedging
Fair hedges carried
Number of interest rate derivatives executed \| derivative	3
Notional amounts	$ 300,000		300,000
Total paid premiums	$ 1,600		$ 1,600
Floor strike rate	3.00%	3.00%	3.00%