Commitments and Financial Instruments with Off-Balance-Sheet Risk (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Loan commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 1,189,671	$ 1,140,892
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments	$ 26,978	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	$ 8,491	$ 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