Fair Value Measurements Fair Value, Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 416	$ 0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	209	181
Securities Available-for-Sale	102,330	60,709
Equity securities	416
Assets, Fair Value Disclosure	102,955	60,890
Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	4,461	2,066
Fair Value, Measurements, Recurring | Federal Home Loan Mortgage Corporation (FHLMC)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	15,378	6,350
Fair Value, Measurements, Recurring | Federal National Mortgage Association (FNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	26,816	23,411
Fair Value, Measurements, Recurring | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	34,479	14,232
Fair Value, Measurements, Recurring | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	16,340
Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	4,856	4,866
Fair Value, Measurements, Recurring | Other investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale		9,784
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Securities Available-for-Sale	16,340	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Securities Available-for-Sale	16,340	0
Equity securities	0
Assets, Fair Value Disclosure	16,340	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Federal Home Loan Mortgage Corporation (FHLMC)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Federal National Mortgage Association (FNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	16,340
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Other investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale		0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Securities Available-for-Sale	85,990	60,276
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Securities Available-for-Sale	85,990	60,276
Equity securities	0
Assets, Fair Value Disclosure	85,990	60,276
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	4,461	2,066
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Federal Home Loan Mortgage Corporation (FHLMC)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	15,378	6,350
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Federal National Mortgage Association (FNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	26,816	23,411
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	34,479	14,232
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	4,856	4,866
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Other investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale		9,351
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	209	181
Securities Available-for-Sale	0	433
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	209	181
Securities Available-for-Sale	0	433
Equity securities	416
Assets, Fair Value Disclosure	625	614
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Government National Mortgage Association (GNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Federal Home Loan Mortgage Corporation (FHLMC)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Federal National Mortgage Association (FNMA)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	0	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available-for-Sale	$ 0	$ 0