Fair Value Measurement of Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Collateral dependent loan charge-offs	$ 2,100	$ 638
Collateral dependent impaired loans, recorded investment	74,600	73,700
Specific valuation allowance allocations	$ 35,500	28,500
Reported net carrying amount of impaired loans		45,200
Valuation of loan servicing rights, discount rate	9.60%
Loan servicing rights, fair value	$ 1,600
Net impairment (recovery of impairment) on loan servicing rights	36	388	$ 429
Foreclosed assets measured at fair value upon initial recognition	10,800	5,700
Allowance for loan losses, charge-offs	3,000	2,000
Loss due to re-measurement of repossessed assets	$ 896	$ 390	$ 361
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Valuation of loan servicing rights, prepayment rate	11.60%
Non-recurring fair value measurements | Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Reported net carrying amount of impaired loans	$ 39,100