Loan Servicing - SBA Loans (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans
Serviced SBA loans sold to secondary market	$ 104,016,000	$ 139,086,000	$ 164,454,000
Weighted average servicing rate for loans serviced (as a percent)	1.12%	1.13%	1.17%

Represents the amount of serviced small business administration loans sold to the secondary market as of the balance sheet date.

No definition available.

Name:	htbk_ServicingAssetLoansHeldForSaleSmallBusinessAdministrationLoansSoldToSecondaryMarket
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant