Investment Securities Investment Securities-Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Mar. 31, 2017
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis		$ 5,054
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis		13,579
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis		39,284
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis		57,917
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value		5,000
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value		13,316
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value		38,170
Available-for-sale		$ 56,486	$ 59,011
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Weighted Average Rate		1.66%
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Weighted Average Rate		2.03%
Available-for-sale Securities, Debt Maturities, after Ten Years, Weighted Average Rate		1.49%
Available-for-sale Securities, Debt Maturities, Weighted Average Rate		1.63%
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount		$ 9,263
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount		3,489
Held-to-maturity	[1]	12,752	13,435
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value		9,364
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value		3,528
Held-to-maturity, Fair Value	[1]	$ 12,892	$ 13,497
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Weighted Average Rate		2.83%
Held-to-maturity Securities, Debt Maturities, after Ten Years, Weighted Average Rate		2.55%
Held-to-maturity Securities, Debt Maturities, Weighted Average Rate		2.75%

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