Represents information pertaining to amount receivable from reinsurer.

No definition available.

Name:	hall_ReceivableFromReinsurer
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of ultimate losses from reinsurance contract.

+ References

No definition available.

+ Details

Name:	hall_ReinsuranceContractLossBeforeIncomeTax
Namespace Prefix:	hall_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of written premiums ceded to other entities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
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-URI https://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

+ Details

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

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

- Definition

Cash paid to make deposits at other institutions during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3536-108585

+ Details

Name:	us-gaap_PaymentsForDepositsWithOtherInstitutions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (b)
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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.5-03(5))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

+ Details

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

- Definition

Amount of reduction of provision for policy benefits and costs incurred for policies ceded.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=99397103&loc=d3e6811-158387

+ Details

Name:	us-gaap_ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount per policy of risk undertaken originally by insurer that is not ceded to reinsurer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=99397103&loc=d3e6811-158387

+ Details

Name:	us-gaap_ReinsuranceRetentionAmountRetainedPerPolicy
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount per policy of risk ceded to reinsurer in excess of risk undertaken originally by insurer that is not ceded to reinsurer.

+ References

+ Details

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

- Details

Name:	srt_LitigationCaseAxis=hall_LossPortfolioTransferContractRightDisputeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationStatusAxis=us-gaap_PendingLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=hall_LossPortfolioTransferReinsuranceContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CededCreditRiskAxis=hall_FirstLayerOfReinsuranceByDaragBermudaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CededCreditRiskAxis=hall_SecondLayerOfReinsuranceByDaragBermudaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CededCreditRiskAxis=hall_TopLayerOfReinsuranceByDaragGuernseyMember
Namespace Prefix:
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Reinsurance (Loss Portfolio Transfer) (Details) - USD ($) $ in Thousands		3 Months Ended
	Jul. 16, 2020	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2020	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Ceded premiums written		$ 14,791	$ 18,064
Receivable from reinsurer		3,953			$ 58,882
Loss Portfolio Transfer Contract Right Dispute [Member] \| Pending Litigation [Member]
Effects of Reinsurance [Line Items]
Write off of receivable		32,900
Receivable from reinsurer		$ 4,000
LPT
Effects of Reinsurance [Line Items]
Pre-tax loss				$ 21,700
Policyholder benefits and claims incurred, ceded	$ 240,000
Ceded premiums written	92,600
Payments for Deposits with Other Institutions	96,700
First Layer Of Reinsurance By DARAG Bermuda [Member] \| LPT
Effects of Reinsurance [Line Items]
Reinsured excess retention amount	151,200
Reinsured retention amount	24,900
Second Layer Of Reinsurance By DARAG Bermuda [Member] \| LPT
Effects of Reinsurance [Line Items]
Reinsured retention amount	27,800
Top Layer Of Reinsurance By DARAG Guernsey [Member] \| LPT
Effects of Reinsurance [Line Items]
Reinsured retention amount	$ 36,100