XML 50 R41.htm IDEA: XBRL DOCUMENT v3.22.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)
$ / shares in Units, $ in Millions
 3 Months Ended
Oct. 18, 2021
USD ($)
$ / shares
shares
Mar. 31, 2022
branch
Restructuring Cost and Reserve [Line Items]    
Number of banking offices | branch   32
Common Stock    
Restructuring Cost and Reserve [Line Items]    
Closing price of BOC's common stock (in USD per share) | $ / shares $ 18.74  
Pacific Mercantile Bancorp (“PMB”)    
Restructuring Cost and Reserve [Line Items]    
Exchange ratio 0.5  
Pacific Mercantile Bancorp (“PMB”)    
Restructuring Cost and Reserve [Line Items]    
Cash paid at closing $ 3.2  
Stock consideration 222.2  
Aggregate purchase price 225.4  
Goodwill $ 58.0  
Pacific Mercantile Bancorp (PMBC)    
Restructuring Cost and Reserve [Line Items]    
Acquisitions shares (in shares) | shares 23,713,417  
Shares paid as merger consideration (in shares) | shares 11,856,713