Commitments and Financial Instruments with Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Loan commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 849,706	$ 829,509
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 34,070	37,984
Standby letters of credit | Minimum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	6 months
Standby letters of credit | Maximum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	1 year
Commercial and similar letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 3,052	$ 741
Commercial and similar letters of credit | Minimum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	3 months
Commercial and similar letters of credit | Maximum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	6 months