Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2020
Entity File Number	1-12431
Entity Registrant Name	UNITY BANCORP INC /NJ/
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	22-3282551
Entity Address, Address Line One	64 Old Highway 22
Entity Address, City or Town	Clinton
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08809
City Area Code	908
Local Phone Number	730-7630
Title of 12(b) Security	Common stock
Trading Symbol	UNTY
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		10,678,794
Entity Central Index Key	0000920427
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false