Deposits - Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits.
Time deposits, including deposits within the CDARS and brokered deposits, $250,000 or more	$ 138,634	$ 163,670

Represents the aggregate amount of domestic and foreign time deposit liabilities including deposits within the Certificate of Deposit Account Registry Service program and brokered deposits in denominations of $250,000 or more.

No definition available.

Name:	htbk_TimeDepositsIncludingDepositsWithinCertificateOfDepositAccountRegistryServiceAndBrokeredDeposits250000OrMore
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant