Loans and Allowance for Credit Losses - Modified Payment Status (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	$ 405	$ 0	$ 429	$ 68
Financial Asset, Not Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			429
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Residential real estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	405		429	68
Residential real estate [Member] | Financial Asset, Not Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			429
Residential real estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Residential real estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Residential real estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Residential real estate [Member] | Senior Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	$ 405		429	$ 68
Residential real estate [Member] | Senior Lien | Financial Asset, Not Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			429
Residential real estate [Member] | Senior Lien | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Residential real estate [Member] | Senior Lien | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0
Residential real estate [Member] | Senior Lien | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			$ 0