Revenue from Contracts with Customers Revenue from Contracts with Customers (Schedule of Contract with Customer, Asset and Liability) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Bank Card Transaction Fees [Member]
Contract with Customer, Asset and Liability [Line Items]
Contract with Customer, Receivable	$ 11,016	$ 13,035	$ 10,978	$ 13,315
Trust Fees [Member]
Contract with Customer, Asset and Liability [Line Items]
Contract with Customer, Receivable	2,720	2,721	3,116	2,802
Deposit Account Charges and Other Fees [Member]
Contract with Customer, Asset and Liability [Line Items]
Contract with Customer, Receivable	5,265	6,107	4,682	5,597
Consumer Brokerage Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Contract with Customer, Receivable	$ 526	$ 559	$ 690	$ 380