CONDENSED FINANCIAL STATEMENTS OF PARENT ONLY - Parent Only Balance Sheet (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Assets          
Cash and due from banks $ 9,151 $ 10,941   $ 10,326  
Other assets 2,997 2,822   2,083  
Total assets 998,519 974,079   902,265  
Liabilities and Shareholders' Equity          
Shareholders' equity 128,272 125,584 $ 117,330 115,777 $ 109,149
Total liabilities and shareholders' equity $ 998,519 974,079   902,265  
PROVIDENT BANCORP, INC.          
Assets          
Cash and due from banks   5,249   5,224  
Investment in common stock of The Provident Bank   117,615   107,629  
Other assets   2,755   2,946  
Total assets   125,619   115,799  
Liabilities and Shareholders' Equity          
Accrued expenses   35   22  
Shareholders' equity   125,584   115,777  
Total liabilities and shareholders' equity   $ 125,619   $ 115,799