Investment Securities-Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	$ 410
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	7,582
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	30,567
Debt Securities, Available-for-sale, Amortized Cost	77,150	$ 89,682
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	410
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	7,644
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	29,897
Available-for-sale	$ 75,268	86,507
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Weighted Average Rate	0.75%
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Weighted Average Rate	1.95%
Available-for-sale Securities, Debt Maturities, after Ten Years, Weighted Average Rate	1.95%
Available-for-sale Securities, Debt Maturities, Weighted Average Rate	1.64%
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount
Held-to-maturity	$ 5,407	7,807
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity
Held-to-maturity, Fair Value	$ 5,592	$ 8,140