Fair Value Measurements - Impaired Loans Remeasured and Reported at Fair Value of Underlying Collateral (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Mar. 31, 2025
Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Carrying value before allocations	$ 6,984	$ 4,243
Specific (allocations) reversals of prior allocations	(791)
Reversal of Specific Valuation Allowance Allocations		19
Fair value	6,193	4,262
Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Carrying value before allocations	20,098	26,991
Specific (allocations) reversals of prior allocations		(1,144)
Reversal of Specific Valuation Allowance Allocations	346
Fair value	$ 20,444	$ 25,847