Represents the number of layers of protection under the reinsurance contract.

No definition available.

Name:	hth_ReinsuranceCoverageNumberOfLayersOfProtection
Namespace Prefix:	hth_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate stated amount that is the upper retention limit per entity policy for per event and sub-catastrophic events.

+ References

No definition available.

+ Details

Name:	hth_ReinsuranceRetentionAggregatePolicyAmountRetained
Namespace Prefix:	hth_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Stated amount that is the retention limit per event policy.

+ References

No definition available.

+ Details

Name:	hth_ReinsuranceRetentionPolicyPerEventRetained
Namespace Prefix:	hth_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the renewal period of reinsurance contract.

+ References

No definition available.

+ Details

Name:	hth_RenewalPeriodOfReinsuranceContract
Namespace Prefix:	hth_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Stated amount that is the upper retention limit per entity policy.

+ References

No definition available.

+ Details

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

- Definition

Amount of risk reinsured in excess of stated retention per company policy.

+ References

No definition available.

+ Details

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

- Definition

Percentage of risk reinsured on insurance products per entity policy.

+ References

No definition available.

+ Details

Name:	us-gaap_ReinsuranceRetentionPolicyReinsuredRiskPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=hth_NationalLloydsCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldforsaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsurancePolicyTypeAxis=hth_CatastrophicCoverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LiabilityForCatastropheClaimsByCatastrophicEventAxis=hth_SubCatastrophicMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	hth_ReinsuranceContractByLayersOfProtectionAxis=hth_FirstLayerOfProtectionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	hth_ReinsuranceContractByLayersOfProtectionAxis=hth_SecondLayerOfProtectionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	hth_ReinsuranceContractByLayersOfProtectionAxis=hth_ThirdLayerOfProtectionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=hth_NationalLloydsInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=hth_AmericanSummitInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsurancePolicyTypeAxis=hth_UnderlyingCoverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Discontinued Operations - Coverage (Details) - Discontinued Operations, Held-for-sale $ in Millions		3 Months Ended	12 Months Ended
	Jul. 01, 2019	Mar. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)
NLC \| Catastrophic Coverage
Reinsurance activity
Renewal period of reinsurance contract	1 year
Number of layers of protection under reinsurance \| item		3
Aggregate coverage in excess of retention for per event retention and sub-catastrophic event			$ 10.0
Retention amount per event			$ 1.0
Participation retained (as a percent)		0.00%	37.50%
NLC \| Catastrophic Coverage \| Maximum
Reinsurance activity
Reinsurance in excess of retention		$ 8.0
NLC \| Catastrophic Coverage \| Sub-catastrophic
Reinsurance activity
Retention amount			$ 15.0
NLC \| Catastrophic Coverage \| First Layer of Protection
Reinsurance activity
Retention amount		8.0
Reinsurance in excess of retention		12.0
NLC \| Catastrophic Coverage \| Second Layer of Protection
Reinsurance activity
Retention amount		20.0
Reinsurance in excess of retention		25.0
NLC \| Catastrophic Coverage \| Third Layer of Protection
Reinsurance activity
Retention amount		45.0
Reinsurance in excess of retention		50.0
NLIC \| Catastrophic Coverage
Reinsurance activity
Retention amount		8.0
ASIC \| Catastrophic Coverage
Reinsurance activity
Retention amount		2.0
ASIC \| Underlying Coverage
Reinsurance activity
Retention amount		2.0
Reinsurance in excess of retention		$ 6.0