Fair Value Measurements-Assets Measured on Recurring basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	$ 0	$ 0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	145	180
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	145	180
Investments, Fair Value Disclosure	65,829	79,845
Assets, Fair Value Disclosure	65,974	80,025
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	3,587	4,382
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	9,538	11,025
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	22,168	26,608
Fair Value, Measurements, Recurring | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	26,481	32,853
Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,055	4,977
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Investments, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | 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, Measurements, Recurring | Fair Value, Inputs, Level 1 | 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, Measurements, Recurring | Fair Value, Inputs, Level 1 | 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, Measurements, Recurring | Fair Value, Inputs, Level 1 | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	0	0
Investments, Fair Value Disclosure	65,829	79,845
Assets, Fair Value Disclosure	65,829	79,845
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | 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	3,587	4,382
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | 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	9,538	11,025
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | 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	22,168	26,608
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	26,481	32,853
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	4,055	4,977
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	145	180
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | 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, Measurements, Recurring | Fair Value, Inputs, Level 3 | 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, Measurements, Recurring | Fair Value, Inputs, Level 3 | 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, Measurements, Recurring | Fair Value, Inputs, Level 3 | US Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 0	$ 0