Investment Securities Investment Securities Text Tags (Details)	3 Months Ended	6 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2018 USD ($)
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		24	35
Available-for-sale		$ 75,109,000	$ 79,845,000
Percentage Available-for-sale Securities		87.60%
Held-to-maturity		$ 10,680,000	11,137,000
Percentage Held-to-maturity Securities		12.40%
Trading		$ 0
Equity Method Investment, Amount Sold	$ 9,200,000
Proceeds from Sale of Available-for-sale Securities		$ 0
Mortgage-backed securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position		40.60%
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months		13
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		1
Held-to-maturity		$ 9,680,000	10,137,000
US Government Agency Securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position		53.70%
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months		3
Corporate Bonds
Schedule of Investments [Line Items]
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months		3
Held-to-maturity		$ 1,000,000	$ 1,000,000
Accounting Standards Update 2016-01
Schedule of Investments [Line Items]
Cumulative Effect of New Accounting Principle				$ 0
Accounting Standards Update 2016-01 | Accumulated Deficit
Schedule of Investments [Line Items]
Cumulative Effect of New Accounting Principle				$ (721,000)