Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 25, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	HERITAGE COMMERCE CORP
Entity Central Index Key	0001053352
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		38,012,326
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1