Credit Quality - Schedule of Amortized Cost Loans Pledged As Collateral (Detail) $ in Thousands	Jun. 30, 2020 USD ($)
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	$ 198,481
Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	53,793
Commercial Real Estate [Member] | Owner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	50,133
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	48,413
Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	25,588
Construction Loans [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	20,554
Consumer Portfolio Segment [Member] | Bankcard [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Consumer Portfolio Segment [Member] | Other Consumer [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	55,970
Residential Real Estate [Member] | Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	6,037
Residential Real Estate [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	2,084
Residential Real Estate [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	12,806
Residential Real Estate [Member] | Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	25,104
Residential Real Estate [Member] | Construction Loans [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	9,939
Residential Real Estate [Member] | Consumer Portfolio Segment [Member] | Bankcard [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Residential Real Estate [Member] | Consumer Portfolio Segment [Member] | Other Consumer [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Business Assets Member [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	48,020
Business Assets Member [Member] | Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	47,707
Business Assets Member [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	84
Business Assets Member [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Business Assets Member [Member] | Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	229
Business Assets Member [Member] | Construction Loans [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Business Assets Member [Member] | Consumer Portfolio Segment [Member] | Bankcard [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Business Assets Member [Member] | Consumer Portfolio Segment [Member] | Other Consumer [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Land [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	13,105
Land [Member] | Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Land [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Land [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	2,981
Land [Member] | Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	255
Land [Member] | Construction Loans [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	9,869
Land [Member] | Consumer Portfolio Segment [Member] | Bankcard [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Land [Member] | Consumer Portfolio Segment [Member] | Other Consumer [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	34,796
Commercial Real Estate [Member] | Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Commercial Real Estate [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	19,246
Commercial Real Estate [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	15,550
Commercial Real Estate [Member] | Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Commercial Real Estate [Member] | Construction Loans [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Commercial Real Estate [Member] | Consumer Portfolio Segment [Member] | Bankcard [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Commercial Real Estate [Member] | Consumer Portfolio Segment [Member] | Other Consumer [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Other Assets [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	46,590
Other Assets [Member] | Commercial Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	49
Other Assets [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	28,719
Other Assets [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	17,076
Other Assets [Member] | Residential Real Estate [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Other Assets [Member] | Construction Loans [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	746
Other Assets [Member] | Consumer Portfolio Segment [Member] | Bankcard [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	0
Other Assets [Member] | Consumer Portfolio Segment [Member] | Other Consumer [Member]
Amortized cost collateral dependent loans [Line Items]
Amortized Cost Loans Pledged As Collateral	$ 0