Investment Securities-Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
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	$ 3,761
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	6,043
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	44,149
Available-for-sale Securities, Amortized Cost Basis	99,814	$ 64,897
Debt Securities, Available-for-sale, Amortized Cost	99,814
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	3,756
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	5,992
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	44,614
Available-for-sale Securities	100,181	65,829
Available-for-sale	$ 100,181	65,829
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Weighted Average Rate	3.04%
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Weighted Average Rate	1.34%
Available-for-sale Securities, Debt Maturities, after Ten Years, Weighted Average Rate	1.85%
Available-for-sale Securities, Debt Maturities, Weighted Average Rate	1.59%
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount
Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five	$ 1,000
Held-to-maturity	9,164	10,151
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity
Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five	1,000
Held-to-maturity, Fair Value	$ 9,551	$ 10,564
Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year One Through Five	4.15%
Held-to-maturity Securities, Debt Maturities, Weighted Average Rate	2.60%

Available-for-sale Securities, Debt Maturities, Weighted Average Rate

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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