Contingent Liabilities, Commitments, and Financial Instruments with Off-Balance-Sheet Risk (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Off-balance-sheet instruments	$ 868,267	$ 829,509
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Off-balance-sheet instruments	33,397	37,984
Commercial and similar letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Off-balance-sheet instruments	$ 1,704	$ 741
Minimum | Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Letter of Credit Term	6 months
Minimum | Commercial and similar letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Letter of Credit Term	3 months
Maximum | Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Letter of Credit Term	1 year
Maximum | Commercial and similar letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information
Letter of Credit Term	6 months