Fair Value Measurements and Disclosures - Off-balance sheet financial instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commitments to extend credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	$ 486,632	$ 421,399
Letters of credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	25,986	8,928
Carrying amount | Level 2 | Commitments to extend credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	486,632	421,399
Carrying amount | Level 2 | Letters of credit
Off-balance sheet financial instruments:
Off-balance sheet financial instruments	$ 25,986	$ 8,928