Investment Securities Text Tags (Details)	6 Months Ended
Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Mar. 31, 2021 USD ($)
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	14		15
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	$ 30,190,000
Debt Securities, Available-for-sale	$ 79,853,000		$ 86,507,000
Percentage Available-for-sale Securities	93.40%
Debt Securities, Held-to-maturity	$ 5,623,000		7,807,000
Percentage Held-to-maturity Securities	6.60%
Trading	$ 0
Mortgage-backed securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	49.80%
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	2
Debt Securities, Available-for-sale	$ 39,644,000		43,421,000
US Government Agency Securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	23.60%
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	3
Debt Securities, Available-for-sale	$ 17,404,000		18,631,000
Municipal Securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	19.90%
Debt Securities, Available-for-sale	$ 17,457,000		$ 16,610,000

Percentage Available-for-sale Securities

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Percentage Held-to-maturity Securities

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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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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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