Loans and the Allowance for Loan Losses (Details) - Loans receivable on nonaccrual status - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans and the Allowance for Loan and Lease Losses (Details) - Loans receivable on nonaccrual status [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 47,680	$ 51,855
Commercial Portfolio Segment [Member]
Loans and the Allowance for Loan and Lease Losses (Details) - Loans receivable on nonaccrual status [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	28,099	29,340
Commercial Real Estate Portfolio Segment [Member]
Loans and the Allowance for Loan and Lease Losses (Details) - Loans receivable on nonaccrual status [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	12,159	15,135
Commercial Construction Portfolio Segment [Member]
Loans and the Allowance for Loan and Lease Losses (Details) - Loans receivable on nonaccrual status [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,934	2,934
Residential Real Estate Portfolio Segment [Member]
Loans and the Allowance for Loan and Lease Losses (Details) - Loans receivable on nonaccrual status [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 4,488	$ 4,446