Fair Value of Financial Instruments Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Financial Assets:
Equity securities	$ 9,710	$ 0
Held-to-maturity, Fair Value	11,603	11,909
Mortgage servicing rights		181
Fair Value, Inputs, Level 1
Financial Assets:
Cash and cash equivalents	92,084	134,558
Securities Available-for-Sale	16,272	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	289,152	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	49,556	60,276
FHLB Stock	566	1,768
Held-to-maturity, Fair Value	11,603	11,909
Loans Receivable	0	0
Accrued interest receivable	1,912	2,023
Mortgage servicing rights	0	0
Other assets - Interest-bearing deposits	972	971
Financial Liabilities:
Deposits	265,300	290,174
Advances from FHLB of New York		24,970
Other borrowed money	13,403	14,565
Accrued interest payable	1,398	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	434,784	469,382
Accrued interest receivable	0	0
Mortgage servicing rights	174	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	92,084	134,558
Securities Available-for-Sale	65,828	60,709
FHLB Stock	566	1,768
Held-to-maturity, Fair Value	11,844	12,075
Loans Receivable	446,709	472,627
Accrued interest receivable	1,912	2,023
Other assets - Interest-bearing deposits	972	971
Financial Liabilities:
Deposits	556,983	586,883
Advances from FHLB of New York		25,000
Other borrowed money	13,403	13,403
Accrued interest payable	1,398	1,086
Estimate of Fair Value Measurement
Financial Assets:
Cash and cash equivalents	92,084	134,558
Securities Available-for-Sale	65,828	60,709
FHLB Stock	566	1,768
Held-to-maturity, Fair Value	11,603	11,909
Loans Receivable	434,784	469,382
Accrued interest receivable	1,912	2,023
Mortgage servicing rights	174	181
Other assets - Interest-bearing deposits	972	971
Financial Liabilities:
Deposits	554,452	535,808
Advances from FHLB of New York		24,970
Other borrowed money	13,403	14,565
Accrued interest payable	$ 1,398	$ 1,086