Loans and Allowance for Credit Losses on Loans - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Loans
2024/2023	$ 275,956	$ 455,535
2023/2022	375,892	642,395
2022/2021	596,205	757,210
2021/2020	719,516	128,649
2020/2019	116,444	217,307
Prior Periods	904,577	743,954
Revolving Loans Amortized Cost Basis	421,973	405,823
Total loan balance	3,410,563	3,350,873
Balance to report	3,362,417	3,302,420
Risk Grades
Loans
2024/2023	275,956	455,535
2023/2022	375,892	642,395
2022/2021	596,205	757,210
2021/2020	719,516	128,649
2020/2019	116,444	217,307
Prior Periods	904,577	743,954
Revolving Loans Amortized Cost Basis	421,973	405,823
Total loan balance	3,410,563	3,350,873
Risk Grades \| Pass
Loans
2024/2023	272,927	449,132
2023/2022	375,745	637,785
2022/2021	590,414	749,811
2021/2020	700,350	127,132
2020/2019	111,857	208,280
Prior Periods	881,461	715,749
Revolving Loans Amortized Cost Basis	418,522	398,528
Total loan balance	3,351,276	3,286,417
Risk Grades \| Special Mention
Loans
2024/2023	3,029	4,270
2023/2022		1,342
2022/2021	5,199	3,344
2021/2020	10,614	462
2020/2019	447	7,626
Prior Periods	5,078	13,072
Revolving Loans Amortized Cost Basis	2,310	2,577
Total loan balance	26,677	32,693
Risk Grades \| Substandard
Loans
2024/2023		2,133
2023/2022	147	2,489
2022/2021	592
2021/2020	4,514	100
2020/2019	3,174	1,285
Prior Periods	16,344	14,362
Revolving Loans Amortized Cost Basis	1,141	4,576
Total loan balance	25,912	24,945
Risk Grades \| Substandard-Nonaccrual
Loans
2023/2022		779
2022/2021		4,055
2021/2020	4,038	955
2020/2019	966	116
Prior Periods	1,694	771
Revolving Loans Amortized Cost Basis		142
Total loan balance	6,698	6,818
Commercial. \| Commercial
Loans
2024/2023	92,596	101,498
2023/2022	28,107	27,858
2022/2021	19,859	20,122
2021/2020	17,981	15,029
2020/2019	11,351	12,327
Prior Periods	35,581	27,874
Revolving Loans Amortized Cost Basis	275,791	259,070
Total loan balance	481,266	463,778
Commercial. \| Commercial \| Pass
Loans
2024/2023	89,567	99,387
2023/2022	27,960	25,250
2022/2021	18,909	19,732
2021/2020	17,627	14,929
2020/2019	11,351	11,893
Prior Periods	30,452	22,134
Revolving Loans Amortized Cost Basis	275,491	258,461
Total loan balance	471,357	451,786
Commercial. \| Commercial \| Special Mention
Loans
2024/2023	3,029	2,107
2023/2022		1,092
2022/2021	358	41
2021/2020	131
2020/2019		133
Prior Periods	185	1,134
Revolving Loans Amortized Cost Basis	200	467
Total loan balance	3,903	4,974
Commercial. \| Commercial \| Substandard
Loans
2024/2023		4
2023/2022	147	1,516
2022/2021	592
2021/2020		100
2020/2019		185
Prior Periods	4,415	3,835
Revolving Loans Amortized Cost Basis	100	142
Total loan balance	5,254	5,782
Commercial. \| Commercial \| Substandard-Nonaccrual
Loans
2022/2021		349
2021/2020	223
2020/2019		116
Prior Periods	529	771
Total loan balance	752	1,236
Real estate \| CRE - Owner Occupied
Loans
2024/2023	42,069	32,993
2023/2022	31,845	86,938
2022/2021	83,140	113,854
2021/2020	110,701	68,646
2020/2019	70,341	53,985
Prior Periods	254,559	216,535
Revolving Loans Amortized Cost Basis	9,407	10,302
Total loan balance	602,062	583,253
Real estate \| CRE - Owner Occupied \| Pass
Loans
2024/2023	42,069	32,993
2023/2022	31,845	86,688
2022/2021	83,140	110,613
2021/2020	102,419	68,184
2020/2019	66,720	52,885
Prior Periods	253,342	214,729
Revolving Loans Amortized Cost Basis	9,407	10,302
Total loan balance	588,942	576,394
Real estate \| CRE - Owner Occupied \| Special Mention
Loans
2023/2022		250
2022/2021		3,241
2021/2020	8,282	462
2020/2019	447
Prior Periods	1,217	1,802
Total loan balance	9,946	5,755
Real estate \| CRE - Owner Occupied \| Substandard
Loans
2020/2019	3,174	1,100
Prior Periods		4
Total loan balance	3,174	1,104
Real estate \| CRE - Non-Owner Occupied
Loans
2024/2023	97,037	225,505
2023/2022	223,427	243,080
2022/2021	237,016	267,870
2021/2020	261,789	28,315
2020/2019	27,272	100,141
Prior Periods	459,604	388,206
Revolving Loans Amortized Cost Basis	4,433	3,473
Total loan balance	1,310,578	1,256,590
Real estate \| CRE - Non-Owner Occupied \| Pass
Loans
2024/2023	97,037	225,505
2023/2022	223,427	243,080
2022/2021	232,175	267,870
2021/2020	255,074	28,315
2020/2019	27,272	92,648
Prior Periods	446,572	370,552
Revolving Loans Amortized Cost Basis	3,833	3,199
Total loan balance	1,285,390	1,231,169
Real estate \| CRE - Non-Owner Occupied \| Special Mention
Loans
2022/2021	4,841
2021/2020	2,201
2020/2019		7,493
Prior Periods	1,279	10,040
Total loan balance	8,321	17,533
Real estate \| CRE - Non-Owner Occupied \| Substandard
Loans
2021/2020	4,514
Prior Periods	11,753	7,614
Revolving Loans Amortized Cost Basis	600	274
Total loan balance	16,867	7,888
Real estate \| Land & Construction
Loans
2024/2023	26,745	44,434
2023/2022	43,646	52,862
2022/2021	30,987	31,125
2021/2020	19,799	10,228
2020/2019	1,180	1,864
Prior Periods	3,404
Total loan balance	125,761	140,513
Real estate \| Land & Construction \| Pass
Loans
2024/2023	26,745	40,142
2023/2022	43,646	52,862
2022/2021	30,987	27,419
2021/2020	15,984	9,273
2020/2019	214	1,864
Total loan balance	117,576	131,560
Real estate \| Land & Construction \| Special Mention
Loans
2024/2023		2,163
Prior Periods	2,323
Total loan balance	2,323	2,163
Real estate \| Land & Construction \| Substandard
Loans
2024/2023		2,129
Total loan balance		2,129
Real estate \| Land & Construction \| Substandard-Nonaccrual
Loans
2022/2021		3,706
2021/2020	3,815	955
2020/2019	966
Prior Periods	1,081
Total loan balance	5,862	4,661
Real estate \| Home Equity
Loans
Prior Periods	2,182	1,463
Revolving Loans Amortized Cost Basis	121,908	117,662
Total loan balance	124,090	119,125
Real estate \| Home Equity \| Pass
Loans
Prior Periods	2,098	1,463
Revolving Loans Amortized Cost Basis	119,357	111,250
Total loan balance	121,455	112,713
Real estate \| Home Equity \| Special Mention
Loans
Revolving Loans Amortized Cost Basis	2,110	2,110
Total loan balance	2,110	2,110
Real estate \| Home Equity \| Substandard
Loans
Revolving Loans Amortized Cost Basis	441	4,160
Total loan balance	441	4,160
Real estate \| Home Equity \| Substandard-Nonaccrual
Loans
Prior Periods	84
Revolving Loans Amortized Cost Basis		142
Total loan balance	84	142
Real estate \| Multi-Family
Loans
2024/2023	13,397	47,089
2023/2022	46,528	41,112
2022/2021	39,833	55,557
2021/2020	54,067	5,394
2020/2019	5,286	42,129
Prior Periods	113,429	78,098
Revolving Loans Amortized Cost Basis	563	355
Total loan balance	273,103	269,734
Real estate \| Multi-Family \| Pass
Loans
2024/2023	13,397	47,089
2023/2022	46,528	41,112
2022/2021	39,833	55,557
2021/2020	54,067	5,394
2020/2019	5,286	42,129
Prior Periods	113,429	75,890
Revolving Loans Amortized Cost Basis	563	355
Total loan balance	273,103	267,526
Real estate \| Multi-Family \| Substandard
Loans
Prior Periods		2,208
Total loan balance		2,208
Real estate \| Residential Mortgage
Loans
2024/2023	3,937	1,684
2023/2022	1,665	189,169
2022/2021	184,031	268,617
2021/2020	255,131	1,037
2020/2019	1,014	6,861
Prior Periods	33,746	29,593
Total loan balance	479,524	496,961
Real estate \| Residential Mortgage \| Pass
Loans
2024/2023	3,937	1,684
2023/2022	1,665	187,417
2022/2021	184,031	268,617
2021/2020	255,131	1,037
2020/2019	1,014	6,861
Prior Periods	33,570	28,892
Total loan balance	479,348	494,508
Real estate \| Residential Mortgage \| Substandard
Loans
2023/2022		973
Prior Periods	176	701
Total loan balance	176	1,674
Real estate \| Residential Mortgage \| Substandard-Nonaccrual
Loans
2023/2022		779
Total loan balance		779
Real estate \| Consumer and Other
Loans
Total loan balance		20,919
Consumer \| Consumer and Other
Loans
2024/2023	175	2,332
2023/2022	674	1,376
2022/2021	1,339	65
2021/2020	48
Prior Periods	2,072	2,185
Revolving Loans Amortized Cost Basis	9,871	14,961
Total loan balance	14,179	20,919
Consumer \| Consumer and Other \| Pass
Loans
2024/2023	175	2,332
2023/2022	674	1,376
2022/2021	1,339	3
2021/2020	48
Prior Periods	1,998	2,089
Revolving Loans Amortized Cost Basis	9,871	14,961
Total loan balance	14,105	20,761
Consumer \| Consumer and Other \| Special Mention
Loans
2022/2021		62
Prior Periods	74	96
Total loan balance	$ 74	$ 158

Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

+ Details

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

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost excluding accrued interest of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_RiskGradesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=htbk_SubstandardNonaccrualMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_CommercialFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_CommercialAndResidentialWithOwnerOccupiedFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_CommercialAndResidentialWithNonOwnerOccupiedFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_LandAndConstructionFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_MultiFamilyResidentialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=htbk_ConsumerLoansAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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