Income Taxes - Components of Low Income Housing Investment (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Income Taxes
Low income housing tax credits	$ 111	$ 172
Low income housing investment losses	$ 117	$ 229

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

No definition available.

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