XML 132 R112.htm IDEA: XBRL DOCUMENT v3.25.0.1

Benefit Plans - Change in Net Actuarial Loss (Gain) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Benefit Plans
Percentage of greater of projected benefit obligation or fair value of plan assets for amortization of actuarial gains or losses	5.00%
Amortization period for actuarial gains and losses that exceed threshold	5 years
Pension Plan [Member]
Change in net actuarial loss (gain) and amortization
Net actuarial loss (gain) at beginning of year	$ 14,599
Amortization cost	(2,209)	$ (2,818)	$ (5,643)
Liability (gain) loss	(4,166)	4,851	(38,949)
Asset loss (gain)	1,190	(3,246)	24,047
Net actuarial loss (gain) at end of year	9,414	14,599
Pension Benefits
Change in net actuarial loss (gain) and amortization
Net actuarial loss (gain) at beginning of year	14,599	15,812
Amortization cost	(2,209)	(2,818)
Liability (gain) loss	(4,166)	4,851
Asset loss (gain)	1,190	(3,246)
Net actuarial loss (gain) at end of year	9,414	14,599	15,812
Other Postretirement Benefits Plan [Member]
Change in net actuarial loss (gain) and amortization
Net actuarial loss (gain) at beginning of year	(7,271)	(8,405)
Amortization cost	1,383	1,676	497
Liability (gain) loss	(963)	(542)	(5,808)
Net actuarial loss (gain) at end of year	$ (6,851)	$ (7,271)	$ (8,405)

X

- Definition

Amortization period of amount included in accumulated other comprehensive income (AOCI) related to actuarial gain (loss) when such gains or losses exceed a percentage threshold.

+ References

No definition available.

+ Details

Name:	fhb_DefinedBenefitPlanFutureAmortizationOfActuarialGainLossAmortizationPeriod
Namespace Prefix:	fhb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The threshold for amortization of amount included in accumulated other comprehensive income (AOCI) related to actuarial gain (loss) as a percentage of the greater of the projected benefit obligation or the fair value of plan assets.

+ References

No definition available.

+ Details

Name:	fhb_DefinedBenefitPlanFutureAmortizationOfActuarialGainLossPercentageThresholdForAmortization
Namespace Prefix:	fhb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount before tax of increase (decrease) in the value of the plan assets resulting from experience different from that assumed, that has not been recognized in net periodic benefit (cost) credit.

+ References

No definition available.

+ Details

Name:	fhb_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTaxAssets
Namespace Prefix:	fhb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount before tax of (increase) decrease in the value of the projected benefit obligation related to a change in an actuarial assumption that has not been recognized in net periodic benefit (cost) credit.

+ References

No definition available.

+ Details

Name:	fhb_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTaxObligations
Namespace Prefix:	fhb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	fhb_PensionAndOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossNetGainsLossesBeforeTaxRollForward
Namespace Prefix:	fhb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- 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

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-15

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 17A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-17A

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RetirementPlanTypeAxis=fhb_PensionPlanOtherPensionPlanAndSupplementalEmployeeRetirementPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: