Deposits (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Domestic Deposits, Brokered [Line Items]
Interest-bearing Domestic Deposit, Brokered	$ 518,192	$ 863,202
Time deposits over $250,000	412,185	355,342
Time deposits $250,000 and under	1,593,453	1,709,980
Time Deposits Balance [Domain]
Domestic Deposits, Brokered [Line Items]
Interest-bearing Domestic Deposit, Brokered	729,400	732,200
Non-maturity Deposits [Member]
Domestic Deposits, Brokered [Line Items]
Interest-bearing Domestic Deposit, Brokered	$ 518,200	$ 835,600