Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Days from origination after which mortgage loan are sold	30 days
Loan upon which a default of principal or interest has existed for a period	90 days
Intangible assets, Estimated useful lives	7 years 7 months 6 days
Advertising costs	$ 3,800	$ 3,500	$ 3,400
Revenue recognition, description of performance obligation	the Company offers various services to customers that generate revenue. Contract performance typically occurs in one year or less.
Incremental cost of obtaining contract	true
Revenue recognition, description of payment terms	Revenue is recognized when the transactions occur or as services are performed over primarily monthly or quarterly periods. Payment is typically received in the period the transactions occur, or in some cases, within 90 days of the service period.
Right-of-use lease assets	$ 5,700			$ 4,300
Lease liabilities	$ 5,620			$ 4,300
Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	7 years 9 months 18 days
Minimum [Member] | ASU No. 2016-13 [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Expected percentage of decrease in allowance for loan loss	0.00%
Minimum [Member] | Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	7 years
Minimum [Member] | Customer Relationship Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	3 years
Maximum [Member] | ASU No. 2016-13 [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Expected percentage of decrease in allowance for loan loss	5.00%
Maximum [Member] | Core Deposit Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	10 years
Maximum [Member] | Customer Relationship Intangibles [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, Estimated useful lives	18 years
Home Equity Lines of Credit [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	9.00%
First Liens [Member] | Minimum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	83.00%
Junior Liens [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Loans and finance receivables portfolio percentage	8.00%