Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Cash and cash equivalents, Carrying Amount	$ 126,203	$ 228,110	$ 301,060	$ 266,743
Investment securities, Carrying Amount	440,863	470,523
Loans, net, Carrying Amount	704,646	676,026
Accrued interest receivable, Carrying Amount	6,834	7,413
Assets, Carrying Amount	1,278,546	1,382,072
Cash and cash equivalents, Fair Value	126,203	228,110
Investment securities, Fair Value	440,863	470,523
Loans, net, Fair Value	697,745	675,020
Accrued interest receivable, Fair Value	6,834	7,413
Assets, Fair Value	1,271,645	1,381,066
Deposits, Carrying Amount	625,737	678,088
Accounts and drafts payable, Carrying Amount	673,704	661,888
Accrued interest payable, Carrying Amount	70	55
Liabilities, Carrying Amount	1,299,511	1,340,031
Deposits, Fair Value	622,973	678,346
Accounts and drafts payable, Fair Value	673,704	661,888
Accrued interest payable, Fair Value	70	55
Liabilities, Fair Value	$ 1,296,747	$ 1,340,289