Allowance for loan and lease losses adoption of CECL transition adjustment.

No definition available.

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

- Definition

Allowance of credit losses from expansion loss horizon of life of loan.

+ References

No definition available.

+ Details

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Namespace Prefix:	hth_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents amount of elimination of allowance of the non-credit component within the allowance of previously categorized purchase credit impairment loans.

+ References

No definition available.

+ Details

Name:	hth_EliminationNoncreditComponentOfPreviouslyCategorizedWithPurchaseCreditImpairment
Namespace Prefix:	hth_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Increase (decrease) in valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

No definition available.

+ Details

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Namespace Prefix:	hth_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=118939070&loc=d3e15032-111544

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Loans Held for Investment - Credit Loss Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Dec. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2018
Allowance for loan losses
Allowance for credit losses	$ 61,136	$ 106,739	$ 58,809	$ 59,486
Transition Adjustment CECL		12,562
Increase in allowance on individually evaluated loans		$ 17,600
ASU 2016-13 \| Restatement
Allowance for loan losses
Allowance for credit losses	73,700
Transition Adjustment CECL	12,600
Allowance in credit loss from expansion of horizon to life of loan	18,900
Non-credit component with allowance of previous categorized PCI loans	$ 6,300