Condensed Financial Statements of Unity Bancorp, Inc. (Parent Company Only) - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 158,016	$ 145,515
Equity securities	2,289	2,144
Premises and equipment, net	21,315	23,371
Prepaid expenses and other assets	7,595	8,635
Total assets	1,718,942	1,579,157
LIABILITIES AND SHAREHOLDERS' EQUITY
Other liabilities	14,354	12,266
Subordinated debentures	10,310	10,310
Shareholders' equity	160,709	138,488	$ 118,105	$ 106,291
Total liabilities and shareholders' equity	1,718,942	1,579,157
Parent Company Only
ASSETS
Cash and cash equivalents	2,308	1,209
Equity securities	1,355	1,239
Investment in subsidiaries	164,881	143,487
Premises and equipment, net	3,849	3,893
Prepaid expenses and other assets	967	1,372
Total assets	173,360	151,200
LIABILITIES AND SHAREHOLDERS' EQUITY
Loan due to subsidiary bank	2,304	2,396
Other liabilities	37	6
Subordinated debentures	10,310	10,310
Shareholders' equity	160,709	138,488
Total liabilities and shareholders' equity	$ 173,360	$ 151,200