Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 28, 2020	Jun. 30, 2019
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	UNITY BANCORP INC /NJ/
Entity Central Index Key	0000920427
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		10,886,274
Entity Public Float			$ 177,801,701
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No