Fair Value of Financial Instruments Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Mar. 31, 2018
Financial Assets:
Equity securities	$ 416	$ 0
Held-to-maturity, Fair Value	11,194	11,909
Fair Value, Inputs, Level 1
Financial Assets:
Cash and cash equivalents	40,073	134,558
Securities Available-for-Sale	16,340	0
FHLB Stock	0	0
Held-to-maturity, Fair Value	0	0
Loans Receivable	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	0	0
Other assets - Interest-bearing deposits	0	0
Financial Liabilities:
Deposits	282,634	245,634
Advances from FHLB of New York		0
Other borrowed money	0	0
Accrued interest payable	0	0
Fair Value, Inputs, Level 2
Financial Assets:
Cash and cash equivalents	0	0
Securities Available-for-Sale	85,990	60,276
FHLB Stock	566	1,768
Held-to-maturity, Fair Value	11,194	11,909
Loans Receivable	0	0
Accrued interest receivable	2,068	2,023
Mortgage servicing rights	0	0
Other assets - Interest-bearing deposits	975	971
Financial Liabilities:
Deposits	227,888	290,174
Advances from FHLB of New York		24,970
Other borrowed money	13,403	14,565
Accrued interest payable	1,684	1,086
Fair Value, Inputs, Level 3
Financial Assets:
Cash and cash equivalents	0	0
Securities Available-for-Sale	0	433
FHLB Stock	0	0
Held-to-maturity, Fair Value	0	0
Loans Receivable	420,568	469,382
Accrued interest receivable	0	0
Mortgage servicing rights	209	181
Other assets - Interest-bearing deposits	0	0
Financial Liabilities:
Deposits	0	0
Advances from FHLB of New York		0
Other borrowed money	0	0
Accrued interest payable	0	0
Reported Value Measurement
Financial Assets:
Cash and cash equivalents	40,073	134,558
Securities Available-for-Sale	102,330	60,709
FHLB Stock	566	1,768
Held-to-maturity, Fair Value	11,340	12,075
Loans Receivable	422,605	472,627
Accrued interest receivable	2,068	2,023
Mortgage servicing rights		181
Other assets - Interest-bearing deposits	975	971
Financial Liabilities:
Deposits	513,017	586,883
Advances from FHLB of New York		25,000
Other borrowed money	13,403	13,403
Accrued interest payable	1,684	1,086
Estimate of Fair Value Measurement
Financial Assets:
Cash and cash equivalents	40,073	134,558
Securities Available-for-Sale	102,330	60,709
Equity securities	416
FHLB Stock	566	1,768
Held-to-maturity, Fair Value	11,194	11,909
Loans Receivable	420,568	469,382
Accrued interest receivable	2,068	2,023
Mortgage servicing rights	209	181
Other assets - Interest-bearing deposits	975	971
Financial Liabilities:
Deposits	510,522	535,808
Advances from FHLB of New York		24,970
Other borrowed money	13,403	14,565
Accrued interest payable	$ 1,684	$ 1,086