Commitments and Financial Instruments with Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Loan commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 1,156,994	$ 1,140,892
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 28,868	24,884
Standby letters of credit | Minimum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	2 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	$ 6,115	$ 7,095
Commercial and similar letters of credit | Minimum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	2 months
Commercial and similar letters of credit | Maximum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Letter of credit term	6 months