Business Combinations - Focus Business Bank - Acquisition and Integration Costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2015
Focus Business Bank
Acquisition and Integration Costs
Pre-tax severance, retention, acquisition and integration costs	$ 2,865	$ 3,407	$ 6,398

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities and costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs

No definition available.

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