Investment Securities Text Tags (Details)	3 Months Ended	9 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	9	9		7
Debt Securities, Available-for-sale	$ 100,181,000	$ 100,181,000		$ 65,829,000
Percentage Available-for-sale Securities	91.60%	91.60%
Debt Securities, Held-to-maturity	$ 9,164,000	$ 9,164,000		10,151,000
Percentage Held-to-maturity Securities	8.40%	8.40%
Trading	$ 0	$ 0
Proceeds from Sale of Available-for-sale Securities	$ 0	$ 30,190,000	$ 0
Mortgage-backed securities
Schedule of Investments [Line Items]
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months	1	1
Debt Securities, Held-to-maturity	$ 8,164,000	$ 8,164,000		$ 9,151,000
US Government Agency Securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	38.70%	38.70%
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months	3	3