Allowance for Credit Losses and Credit Quality Information (Assessment of Credit Quality) (Details) - USD ($)	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2021
Financing Receivable, Recorded Investment [Line Items]
Impaired loans	$ 57,200,000	$ 47,000,000.0
Gross loans receivable	1,209,871,366		$ 1,104,746,261
New borrower
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	124,800,193
Former borrower
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	127,108,125
Refinance
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	935,448,882
Delinquent refinance
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	22,514,166
Performing Financing Receivables
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	1,104,130,714
Nonperforming Financing Receivables
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	105,740,652
Consumer loans- non-bankrupt accounts
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	1,203,552,152
Consumer loans- bankrupt accounts
Financing Receivable, Recorded Investment [Line Items]
Gross loans receivable	$ 6,319,214