Loans and Allowance for Credit Losses - Schedule of Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Mar. 31, 2026
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	$ 5,890	$ 5,439	$ 5,809	$ 5,441	$ 5,441
Provision for (reversal of) credit losses	(13)	89	38	86
Loans Charged off	(1)	(7)	(5)	(7)
Recoveries	14	2	48	3
Ending Allowance Balance	5,890	5,523	5,890	5,523	5,809
Real Estate \| Construction
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	247	246	356	246	246
Provision for (reversal of) credit losses	0	39	(109)	39
Ending Allowance Balance	247	285	247	285	356
Real Estate \| Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	1,973	1,572	1,787	1,572	1,572
Provision for (reversal of) credit losses	0	116	186	116
Ending Allowance Balance	1,973	1,688	1,973	1,688	1,787
Real Estate \| Residential
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	1,702	1,925	1,784	1,926	1,926
Provision for (reversal of) credit losses	(0)	(125)	(82)	(126)
Ending Allowance Balance	1,702	1,800	1,702	1,800	1,784
Commercial \| Non-Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	981	667	991	667	667
Provision for (reversal of) credit losses	0	128	(10)	128
Ending Allowance Balance	981	795	981	795	991
Agriculture
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	694	476	558	476	476
Provision for (reversal of) credit losses	0	83	136	83
Ending Allowance Balance	694	559	694	559	558
Other Consumer
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	120	261	135	262	262
Provision for (reversal of) credit losses	(0)	(88)	(11)	(90)
Loans Charged off	(1)	(7)	(5)	(7)
Recoveries	0	2	0	3
Ending Allowance Balance	119	168	119	168	135
Land Development and SIDs
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning Allowance Balance	173	292	198	292	292
Provision for (reversal of) credit losses	(13)	(64)	(72)	(64)
Recoveries	14		48
Ending Allowance Balance	$ 174	$ 228	$ 174	$ 228	$ 198

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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