Represents the number of business units of the entity.

No definition available.

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Balance Type:	na
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- Definition

Represents line items for significant accounting policies table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(12))
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(11))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=hth_BoroMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_OwnershipAxis=hth_PlainsCapitalCorporationMember
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Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_OwnershipAxis=hth_SecuritiesHoldingsMember
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Data Type:	na
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- Details

Name:	us-gaap_OwnershipAxis=hth_NationalLloydsCorporationMember
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Data Type:	na
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Period Type:

- Details

Name:	dei_LegalEntityAxis=hth_PlainsCapitalCorporationMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_OwnershipAxis=hth_PlainsCapitalBankMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_OwnershipAxis=hth_PCCStatutoryTrustsMember
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- Details

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- Details

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Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
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Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_OwnershipAxis=hth_PrimeLendingVenturesManagementLLCMember
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- Details

Name:	dei_LegalEntityAxis=hth_BoroMember
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Summary of Significant Accounting and Reporting Policies - Basis of Presentation, Ownership (Details) $ in Thousands		3 Months Ended
	Feb. 13, 2018 USD ($)	Mar. 31, 2018 USD ($) item	Dec. 31, 2017 USD ($)
Basis of Presentation
Number of primary business units \| item		3
Assets		$ 13,346,126	$ 13,365,786
Deposits		$ 7,959,722	7,978,119
BORO
Basis of Presentation
Aggregate purchase price, cash	$ 85,000
PPC
Basis of Presentation
Ownership percentage		100.00%
Securities Holdings
Basis of Presentation
Ownership percentage		100.00%
NLC
Basis of Presentation
Ownership percentage		100.00%
PPC \| PlainsCapital
Basis of Presentation
Ownership percentage		100.00%
PPC \| PCC Statutory Trusts
Basis of Presentation
Ownership percentage		100.00%
PlainsCapital \| Hilltop Opportunity Partners LLC
Basis of Presentation
Membership ownership percentage		100.00%
PlainsCapital \| PrimeLending
Basis of Presentation
Ownership percentage		100.00%
PrimeLending \| Ventures Management
Basis of Presentation
Membership ownership percentage		100.00%
BORO
Basis of Presentation
Assets			454,000
Loans			344,000
Deposits			$ 406,000