Loans - Troubled Debt Restructurings (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Loans
Recorded investment of troubled debt restructurings	$ 434,000	$ 133,000
Troubled debt restructurings, nonaccrual loans	91,000	2,000
Troubled debt restructurings, accruing loans	343,000	131,000
Specific reserves	$ 36,000	$ 2,000

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.

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

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=25495931&loc=d3e18845-111554

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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- References

No definition available.

+ Details

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