Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Undisbursed loans and unused lines of credit
Financial Instruments with Off-Balance Sheet Risk
Allowance for credit losses	$ 1,100	$ 603
Commitments to extend credit
Financial Instruments with Off-Balance Sheet Risk
Financial instruments with off-balance sheet risk	581,000	$ 415,000
Undisbursed Commitments For C&I Loans
Financial Instruments with Off-Balance Sheet Risk
Financial instruments with off-balance sheet risk	$ 332,000