Investment Securities Investment Securities Text Tags (Details)		Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)
Schedule of Investments [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		31	33
Available-for-sale		$ 56,486,000	$ 59,011,000
Percentage Available-for-sale Securities		81.60%
Held-to-maturity	[1]	$ 12,752,000	13,435,000
Percentage Held-to-maturity Securities		18.40%
Trading Securities		$ 0
Mortgage-backed securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position		61.80%
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months		16
Available-for-sale		$ 34,690,000	36,703,000
Other investments
Schedule of Investments [Line Items]
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months		1
Available-for-sale	[2]	$ 9,913,000	9,862,000
Corporate Bonds
Schedule of Investments [Line Items]
Number of AFS securities in Unrealized Loss Positions, greater than or equal to 12 months		5
Available-for-sale		$ 5,013,000	$ 4,964,000

[1] * The carrying amount and amortized cost are the same for all held-to-maturity securities, as no OTTI has been recorded.

[2] (1) Primarily comprised of an investment in a CRA fund with 95% of its underlying investments consisting of government and agency-backed securities.