Name:	htbk_FinancingReceivableModificationsDefaultPeriod
Namespace Prefix:	htbk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the modification impact on allowance at the end of the period.

No definition available.

Name:	htbk_FinancingReceivableModificationsImpactOnAllowance
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of financing receivables that have been modified during the period by troubled debt restructurings.

No definition available.

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Namespace Prefix:	htbk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Amount of investment in financing receivables (after modification) modified during the period by troubled debt restructurings.

No definition available.

Name:	htbk_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of investment in financing receivables (before modification) modified during the period by troubled debt restructurings.

No definition available.

Name:	htbk_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings and are on nonaccrual status as of the balance sheet date.

No definition available.

Name:	htbk_FinancingReceivableModificationsRecordedInvestmentNonaccrualStatus
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Represents the amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings and are still accruing as of the balance sheet date.

No definition available.

Name:	htbk_FinancingReceivableModificationsRecordedInvestmentStillAccruing
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 65

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7484272&loc=SL7484277-172609

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

- Details

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

Number of financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 33

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953676-111524

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6951948&loc=d3e18845-111554

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 34

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953682-111524

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

Reflects the amount of the write-down related to a troubled debt restructuring.