XML 41 R60.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
ACQUISITION - COMMERCE NARATIVE (Details) - SI Financial Group, Inc.
$ / shares in Units, $ in Thousands
 12 Months Ended
May 17, 2019
USD ($)
branch
$ / shares
shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Business Acquisition [Line Items]      
Equity interest issued or issuable, shares converted (in shares) | shares 11,858,000    
Equity interest, share exchange ratio 0.48    
Business acquisition, equity interest issued (shares) | shares 5,691,000    
Company common stock issued to SIFI common shareholders | $ $ 175,804    
Equity interest issued or issuable, basis for determining value, share price (in dollars per share) | $ / shares $ 30.89    
Fair value of SIFI stock options converted to Berkshire options | $ $ 907    
Direct acquisition and integration costs | $   $ 18,700 $ 2,800
Pro forma estimated tax rate   27.04% 27.04%
Eastern Connecticut      
Business Acquisition [Line Items]      
Number of branch banking offices | branch 18    
Rhode Island      
Business Acquisition [Line Items]      
Number of branch banking offices | branch 5    
Connecticut      
Business Acquisition [Line Items]      
Number of branch banking offices | branch 9