Loans and Leases (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Unamortized deferred loan origination fees and costs $ 14.9 $ 15.7  
Percentage of loans to aggregate outstanding amount in the greater New York/New Jersey Metropolitan area and northeastern states 27.80%    
Percentage of loans to aggregate outstanding amount in Other areas of the United States 72.20%    
Loans and leases pledged as collateral $ 3,000.0   $ 3,000.0
Loans And Leases Receivable      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Accrued interest receivable $ 18.4 $ 17.4