Investment Securities Text Tag (Details)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	7	35
Cumulative Effect of New Accounting Principle	$ 5,300,000
Debt Securities, Available-for-sale	$ 65,829,000	$ 79,845,000
Percentage Available-for-sale Securities	86.60%
Debt Securities, Held-to-maturity	$ 10,151,000	$ 11,137,000
Percentage Held-to-maturity Securities	13.40%
Debt Securities, Trading, and Equity Securities, FV-NI	$ 0
Cumulative Effect of New Accounting Principle	5,300,000
Equity securities	874,000
Financial Instruments, Owned and Pledged as Collateral, at Fair Value	$ 21,000,000.0
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	7	35
Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Cumulative Effect of New Accounting Principle		$ 0
Cumulative Effect of New Accounting Principle		0
Mortgage-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	1
Debt Securities, Held-to-maturity	$ 9,151,000	10,137,000
US Government Agency Securities
Debt Securities, Available-for-sale [Line Items]
Percentage Available-for-Sale, Continuous Unrealized Loss Position	89.10%
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	3
Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Percentage Available-for-Sale, Continuous Unrealized Loss Position	8.30%
Debt Securities, Held-to-maturity	$ 1,000,000	1,000,000
Accumulated Deficit | Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Cumulative Effect of New Accounting Principle		(721,000)
Cumulative Effect of New Accounting Principle		$ (721,000)