Credit Quality - Schedule of Amortized Cost Basis Payment Status (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Current [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	$ 51,404	$ 1,771
Current [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	474	0
Current [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	38,736	1,771
Current [Member] | Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	2,474	0
Current [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	9,420	0
Current [Member] | Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	300	0
Current [Member] | Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
Current [Member] | Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
30-89 Days Past Due [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	95
30-89 Days Past Due [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
30-89 Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
30-89 Days Past Due [Member] | Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
30-89 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	95
30-89 Days Past Due [Member] | Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
30-89 Days Past Due [Member] | Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
30-89 Days Past Due [Member] | Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	0	0
90+ Days Past Due [Member] | Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Payment Status (Amortized Cost Basis)	$ 0	$ 0