INVESTMENTS - Schedule of Net Investment Gain (Details) - EBP 310 $ in Thousands	12 Months Ended
Dec. 31, 2025 USD ($)
Investment income:
Total investment income	$ 69,897
Master Trust Balances
Investment income:
Net appreciation in fair value of investments	1,086,929
Dividends	13,646
Interest	24,075
Administrative and investment expenses	(8,819)
Total investment income	$ 1,115,831

EBP, Change In Net Asset Available For Benefit, Decrease From Administrative And Investment Expense

No definition available.

Name:	hii_EBPChangeInNetAssetAvailableForBenefitDecreaseFromAdministrativeAndInvestmentExpense
Namespace Prefix:	hii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase (decrease) in net asset available for benefit from realized and unrealized gain (loss) on investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477783/962-325-50-7

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-7

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in net asset available for benefit from income (loss) on investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, realized and unrealized gain (loss) on investment.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestment
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForIncomeLossOnInvestmentAbstract
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase in net asset available for benefit from dividend income on investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(1)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477783/962-325-50-7

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-7

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForDividendIncomeOnInvestment
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase in net asset available for benefit from interest income on investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Excludes interest income on note receivable from participant.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477783/962-325-50-7

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-7

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(1)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestIncomeOnInvestment
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=hii_EBP310Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustAndPlanInterestInMasterTrustAxis=us-gaap-ebp_EmployeeBenefitPlanNonconsolidatedMasterTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: