Name:	htbk_BusinessCombinationAcquiredReceivablesEstimatedUncollectibleImpairedLoans
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of nonimpaired loans acquired.

No definition available.

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

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual amounts of impaired loans.

No definition available.

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

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the gross contractual nonimpaired loans.

No definition available.

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

Represents contractual cash flows not expected to be collected on impaired loans as a percent of the gross contractual amount.

No definition available.

Name:	htbk_BusinessCombinationAcquiredReceivablesImpairedLoansEstimatedUncollectiblePercentageOfGrossContractualAmount
Namespace Prefix:	htbk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the number of impaired loans acquired in a business combination.

No definition available.

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

Represents the purchase discount on nonimpaired loans receivable acquired in a business combination.

No definition available.

Name:	htbk_BusinessCombinationAcquiredReceivablesPurchaseDiscountNonimpairedLoans
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the purchase discount on nonimpaired loans receivable acquired in a business combination as a percentage of gross outstanding principal balances.

No definition available.

Name:	htbk_BusinessCombinationAcquiredReceivablesPurchaseDiscountNonimpairedLoansPercentage
Namespace Prefix:	htbk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Amount of income tax attributes related to the purchase accounting adjustments.

No definition available.

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

- References

No definition available.

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

For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of the receivables acquired, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

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

- References

No definition available.

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

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266