Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 14, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	000-23877
Entity Registrant Name	HERITAGE COMMERCE CORP
Entity Incorporation, State or Country Code	CA
Entity Tax Identification Number	77-0469558
Entity Address, Address Line One	224 Airport Parkway
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95110
City Area Code	408
Local Phone Number	947-6900
Title of 12(b) Security	Common Stock, No Par Value
Trading Symbol	HTBK
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		61,169,473
Entity Central Index Key	0001053352
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Annual Report	true
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
ICFR Auditor Attestation Flag	true
Entity Public Float			$ 400.2
Auditor Name	Crowe LLP
Auditor Firm ID	173
Auditor Location	Oak Brook, Illinois
Document Financial Statement Error Correction [Flag]	false