Allowance for Credit Losses - Loans Modified (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2026 USD ($)
Allowance for Credit Losses
Total Class of Financing Receivable	0.01%
Principal Forgiveness
Allowance for Credit Losses
$ Amount	$ 15
Term Extension
Allowance for Credit Losses
$ Amount	31
Interest Rate Reduction
Allowance for Credit Losses
$ Amount	103
Combination Term Extension and Principal Forgiveness
Allowance for Credit Losses
$ Amount	229
Combination Term Extension Interest Rate Reduction
Allowance for Credit Losses
$ Amount	$ 225
Residential \| First Liens
Allowance for Credit Losses
Total Class of Financing Receivable	0.03%
Residential \| First Liens \| Term Extension
Allowance for Credit Losses
$ Amount	$ 12
Residential \| First Liens \| Interest Rate Reduction
Allowance for Credit Losses
$ Amount	103
Residential \| First Liens \| Combination Term Extension Interest Rate Reduction
Allowance for Credit Losses
$ Amount	$ 50
Residential \| Junior Liens
Allowance for Credit Losses
Total Class of Financing Receivable	0.09%
Residential \| Junior Liens \| Term Extension
Allowance for Credit Losses
$ Amount	$ 14
Residential \| Junior Liens \| Combination Term Extension Interest Rate Reduction
Allowance for Credit Losses
$ Amount	$ 52
Residential \| All Other Residential
Allowance for Credit Losses
Total Class of Financing Receivable	0.20%
Residential \| All Other Residential \| Combination Term Extension Interest Rate Reduction
Allowance for Credit Losses
$ Amount	$ 74
Consumer \| Motor Vehicle
Allowance for Credit Losses
Total Class of Financing Receivable	0.04%
Consumer \| Motor Vehicle \| Principal Forgiveness
Allowance for Credit Losses
$ Amount	$ 15
Consumer \| Motor Vehicle \| Term Extension
Allowance for Credit Losses
$ Amount	5
Consumer \| Motor Vehicle \| Combination Term Extension and Principal Forgiveness
Allowance for Credit Losses
$ Amount	229
Consumer \| Motor Vehicle \| Combination Term Extension Interest Rate Reduction
Allowance for Credit Losses
$ Amount	$ 49