Allowance for Loan and Lease Losses (Narrative) (Details)
3 Months Ended
Mar. 31, 2020
USD ($)
loan
Mar. 31, 2019
USD ($)
loan
Jan. 01, 2020
USD ($)
Dec. 31, 2019
USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Unfunded credit commitments liability included in other liabilities $ 17,200,000     $ 1,900,000
Unfunded credit commitments liability charged off 0 $ 0    
Allowance for loan and lease losses       61,082,000
General allowance for loan and lease losses 107,900,000     59,300,000
Specific allowance for loan and lease losses 5,300,000     1,800,000
Increase (decrease) in specific portion of the allowance for loan and lease losses 3,500,000      
Increase (decrease) in total debt restructured loans and leases (900,000)      
Total troubled debt restructurings 22,299,000     23,180,000
Recorded investment, at end of period 500,000 $ 17,600,000    
Decrease from TDR loans and leases that were modified $ 16,500,000      
TDR loans and leases with more than one modification | loan 0 0    
Financial impact of modification of performing and nonperforming loans $ 134,000 $ 878,000    
Commitments to lend funds to debtors owing receivables whose terms had been modified in troubled debt restructurings 2,300,000 $ 2,800,000    
Originated        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses 113,181,000     58,867,000
Commercial real estate        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Increase (decrease) in specific portion of the allowance for loan and lease losses 1,700,000      
Commercial        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Increase (decrease) in specific portion of the allowance for loan and lease losses 2,200,000      
Commercial loans        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses       24,826,000
Commercial loans | Originated        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses 26,774,000     24,525,000
Commercial real estate loans        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses       30,285,000
Commercial real estate loans | Originated        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses 82,179,000     28,422,000
Consumer loans        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses       5,971,000
Consumer loans | Originated        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses $ 4,228,000     $ 5,920,000
Accounting Standards Update 2016-13        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan and lease losses     $ 6,600,000