Short-Term Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Short-term borrowings
Total short-term borrowings	$ 89,814	$ 109,676
Securities sold under agreements to repurchase
Short-term borrowings
Total short-term borrowings	6,814	9,676
Federal Home Loan Bank short-term advances
Short-term borrowings
Total short-term borrowings	$ 83,000	$ 100,000