LOANS AND THE ALLOWANCE FOR LOAN LOSSES - Summary (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	$ 29,723	$ 22,542	$ 22,299	$ 20,509
Provision for loan losses	2,174	684	10,102	3,266
Charge-offs	(1,078)	(937)	(2,459)	(2,436)
Recoveries	835	472	1,712	1,422
Allowance for loan losses at end of period	31,654	22,761	31,654	22,761
Commercial and industrial
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	4,356	5,187	4,441	3,748
Provision for loan losses	(98)	(915)	565	700
Charge-offs	(881)	(32)	(1,690)	(315)
Recoveries	517	313	578	420
Allowance for loan losses at end of period	3,894	4,553	3,894	4,553
Agricultural and farmland
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	2,890	2,862	2,766	2,650
Provision for loan losses	(585)	(133)	(434)	109
Charge-offs			(27)	(30)
Allowance for loan losses at end of period	2,305	2,729	2,305	2,729
Commercial real estate - owner occupied
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	3,257	2,487	1,779	2,506
Provision for loan losses	86	(482)	1,124	(356)
Charge-offs	(39)	(216)	(39)	(382)
Recoveries		26	440	47
Allowance for loan losses at end of period	3,304	1,815	3,304	1,815
Commercial real estate - non-owner occupied
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	6,767	2,721	3,663	2,644
Provision for loan losses	2,496	521	5,591	588
Charge-offs		(111)	(56)	(111)
Recoveries	5	5	70	15
Allowance for loan losses at end of period	9,268	3,136	9,268	3,136
Multi-family
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	1,581	1,153	1,024	912
Provision for loan losses	614	(182)	1,171	59
Charge-offs		(41)		(41)
Allowance for loan losses at end of period	2,195	930	2,195	930
Construction and land development
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	3,366	3,723	2,977	4,176
Provision for loan losses	179	(601)	551	(1,478)
Charge-offs	(26)		(27)	(9)
Recoveries	198	1	216	434
Allowance for loan losses at end of period	3,717	3,123	3,717	3,123
One-to-four family residential
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	3,010	3,569	2,540	2,782
Provision for loan losses	138	(692)	598	541
Charge-offs	(42)	(387)	(154)	(1,026)
Recoveries	46	42	168	235
Allowance for loan losses at end of period	3,152	2,532	3,152	2,532
Municipal, consumer, and other
Activity in the allowance for loan losses
Allowance for loan losses at beginning of period	4,496	840	3,109	1,091
Provision for loan losses	(656)	3,168	936	3,103
Charge-offs	(90)	(150)	(466)	(522)
Recoveries	69	85	240	271
Allowance for loan losses at end of period	$ 3,819	$ 3,943	$ 3,819	$ 3,943

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: 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=121614798&loc=d3e15032-111544

Reference 3: 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=121611835&loc=SL6953423-111524

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-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

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

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_AgriculturalAndFarmlandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_CommercialRealEstateOwnerOccupiedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_CommercialRealEstateNonOwnerOccupiedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_MultiFamilyLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_ConstructionAndLandDevelopmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_OneToFourFamilyResidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=hbt_MunicipalConsumerAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: