Fair Value, Assets Measured on Recurring Basis, Valuation Techniques (Details) $ in Thousands		9 Months Ended	12 Months Ended
		Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)
Fair Value, Inputs, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights		$ 172	$ 180
Other investments		629
Fair Value, Measurements, Recurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights		172	180
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights			180
Fair Value, Measurements, Recurring | Other Assets | Fair Value, Inputs, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		$ 172	$ 180	$ 209	$ 181
Fair Value Measurements, Valuation Processes, Description		Discounted Cash Flow	Discounted Cash Flow
Servicing Asset, Measurement Input		0.0941	0.1119
Measurement Input, Constant Prepayment Rate | Fair Value, Measurements, Recurring | Other Assets | Fair Value, Inputs, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Measurements, Valuation Processes, Description	[1]	Weighted Average Constant Prepayment Rate(1)	Weighted Average Constant Prepayment Rate(1)
Measurement Input, Discount Rate | Fair Value, Measurements, Recurring | Other Assets | Fair Value, Inputs, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Measurements, Valuation Processes, Description	[1]	Option Adjusted Spread ("OAS") applied to Treasury curve	Option Adjusted Spread ("OAS" applied to Treasury curve

[1] ⁽¹⁾ Represents annualized loan repayment rate assumptions