Income Taxes - Components of Low Income Housing Investment (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Taxes
Low income housing tax credits	$ 210,000	$ 210,000	$ 420,000	$ 420,000
Low income housing investment expense	$ 211,000	$ 209,000	$ 421,000	$ 418,000

Represents information pertaining to investment expense on income tax housing investment.

No definition available.

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