Fair Value - Carrying Amount and Estimated Fair Value of Financial Assets and Liabilities (Details) - Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2026	Mar. 31, 2025
Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	$ 384,224	$ 144,864
Held-to-maturity securities, net	707,823	718,191
Non-marketable securities, at cost	15,549	15,549
Loans and leases, net	3,539,953	3,572,570
Financial liabilities:
Total deposits	5,116,273	4,977,826
Subordinated debentures	10,310	10,310
Fair Value [Member]
Financial assets:
Cash and cash equivalents	384,224	144,864
Held-to-maturity securities, net	581,514	592,736
Non-marketable securities, at cost	15,549	15,549
Loans and leases, net	3,568,049	3,591,336
Financial liabilities:
Total deposits	5,113,421	4,975,673
Subordinated debentures	10,712	10,810
Level 1 [Member] | Fair Value [Member]
Financial assets:
Cash and cash equivalents	384,224	144,864
Held-to-maturity securities, net	0	0
Non-marketable securities, at cost	0	0
Loans and leases, net	0	0
Financial liabilities:
Total deposits	0	0
Subordinated debentures	0	0
Level 2 [Member] | Fair Value [Member]
Financial assets:
Cash and cash equivalents	0	0
Held-to-maturity securities, net	531,523	542,161
Non-marketable securities, at cost	15,549	15,549
Loans and leases, net	0	0
Financial liabilities:
Total deposits	5,113,421	4,975,673
Subordinated debentures	10,712	10,810
Level 3 [Member] | Fair Value [Member]
Financial assets:
Cash and cash equivalents	0	0
Held-to-maturity securities, net	49,991	50,575
Non-marketable securities, at cost	0	0
Loans and leases, net	3,568,049	3,591,336
Financial liabilities:
Total deposits	0	0
Subordinated debentures	$ 0	$ 0