Off-Balance-Sheet Arrangements, Commitments and Contingencies (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk, at fair value	$ 1,010,721	$ 901,995
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk, at fair value	983,197	874,557
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk, at fair value	$ 27,524	$ 27,438