Short-Term Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Short-term borrowings
Total short-term borrowings	$ 109,676	$ 422,279
Securities sold under agreements to repurchase
Short-term borrowings
Total short-term borrowings	9,676	22,279
Federal Home Loan Bank short-term advances
Short-term borrowings
Total short-term borrowings	$ 100,000	$ 400,000