Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Loans and Allowance For Credit Losses - Summary of Outstanding Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable Gross	$ 1,301,972		$ 1,369,070
Deferred loan origination costs, net	760		523
Allowance for credit losses	(13,571)	$ (13,240)	(14,111)	$ (13,385)	$ (12,524)	$ (11,075)
Total loans, net	1,289,161		1,355,482
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable Gross	428,169		414,548
Allowance for credit losses	(8,209)	(8,133)	(8,923)	(8,634)	(7,851)	(6,708)
Real Estate - Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable Gross	664,202		550,690
Real Estate - Construction & Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable Gross	41,312		37,193
Allowance for credit losses	(675)	(697)	(681)	(676)	(956)	(1,022)
SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable Gross	107,096		317,564
Allowance for credit losses	(273)	(317)	(604)	(445)	(366)	(50)
Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable Gross	61,193		49,075
Allowance for credit losses	$ (21)	$ (24)	$ (26)	$ (22)	$ (19)	$ (14)