Income Taxes - Components of Low Income Housing Investment (Details) - USD ($)	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Income Taxes
Low income housing tax credits	$ 141,000	$ 180,000
Low income housing investment expense	$ 148,000	$ 186,000

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