Investment Securities-Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Sep. 30, 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, within One Year, Amortized Cost	$ 1,001
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	3,763
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	6,402
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	44,521
Available-for-sale Securities, Amortized Cost Basis	103,054	$ 64,897
Debt Securities, Available-for-sale, Amortized Cost	103,054
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	1,002
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	3,723
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	6,343
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	44,463
Available-for-sale Securities	103,075	65,829
Available-for-sale	$ 103,075	65,829
Available-for-sale, Securities, Debt Maturities, within One Year, Weighted Average Rate	1.71%
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	1.32%
Available-for-sale Securities, Debt Maturities, after Ten Years, Weighted Average Rate	1.84%
Available-for-sale Securities, Debt Maturities, Weighted Average Rate	1.58%
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	9,501	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	991
Held-to-maturity, Fair Value	$ 9,917	$ 10,564
Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year One Through Five	4.23%
Held-to-maturity Securities, Debt Maturities, Weighted Average Rate	2.82%

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

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Held-to-maturity 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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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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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), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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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), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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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), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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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), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount 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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Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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