Short-term Borrowings (Short-term Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Short-term borrowings	$ 227,010	$ 324,691
Securities sold under agreement to repurchase
Short-term Debt [Line Items]
Short-term borrowings	80,124	107,957
Federal funds purchased
Short-term Debt [Line Items]
Short-term borrowings	35,400	168,250
Advances from the FHLB
Short-term Debt [Line Items]
Short-term borrowings	100,838	40,000
Other short-term borrowings
Short-term Debt [Line Items]
Short-term borrowings	$ 10,648	$ 8,484