Fair Value Measurements (Assets Measured at Fair Value on a Recurring Basis) (Details)	12 Months Ended
	Mar. 31, 2018 USD ($)
Summary of Assets Measured at Fair Value on a Recurring Basis
Fair Value, Assets, Level 1, Level 2, or Level 3 Transfers, Amount	$ 0
Recurring [Member] | Securities issued by the U.S Treasury and Government [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(293,000)	[1]
Recurring [Member] | Mortgage-backed securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(7,499,000)	[1]
Recurring [Member] | Securities issued by states and political subdivisions [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(6,337,000)	[1]
Recurring [Member] | Corporate Debt Securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(2,052,000)	[1]
Recurring [Member] | Marketable equity securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(8,695,000)	[1]
Level 1 [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity, Fair Value Disclosure	0
Level 1 [Member] | Recurring [Member] | Securities issued by the U.S Treasury and Government [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 1 [Member] | Recurring [Member] | Mortgage-backed securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 1 [Member] | Recurring [Member] | Securities issued by states and political subdivisions [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 1 [Member] | Recurring [Member] | Corporate Debt Securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 1 [Member] | Recurring [Member] | Marketable equity securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(8,695,000)	[1]
Level 2 [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity, Fair Value Disclosure	0
Level 2 [Member] | Recurring [Member] | Securities issued by the U.S Treasury and Government [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(293,000)	[1]
Level 2 [Member] | Recurring [Member] | Mortgage-backed securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(7,499,000)	[1]
Level 2 [Member] | Recurring [Member] | Securities issued by states and political subdivisions [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(6,337,000)	[1]
Level 2 [Member] | Recurring [Member] | Corporate Debt Securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(2,052,000)	[1]
Level 2 [Member] | Recurring [Member] | Marketable equity securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 3 [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity, Fair Value Disclosure	18,853,000
Level 3 [Member] | Recurring [Member] | Securities issued by the U.S Treasury and Government [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 3 [Member] | Recurring [Member] | Mortgage-backed securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 3 [Member] | Recurring [Member] | Securities issued by states and political subdivisions [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 3 [Member] | Recurring [Member] | Corporate Debt Securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Level 3 [Member] | Recurring [Member] | Marketable equity securities [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[1]
Mortgage Servicing Rights [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(1,410,000)	[2]
Mortgage Servicing Rights [Member] | Level 1 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[2]
Mortgage Servicing Rights [Member] | Level 2 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[2]
Mortgage Servicing Rights [Member] | Level 3 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(1,410,000)	[2]
Forward loan sale commitments [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(26,000)	[3]
Forward loan sale commitments [Member] | Level 1 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[3]
Forward loan sale commitments [Member] | Level 2 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[3]
Forward loan sale commitments [Member] | Level 3 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(26,000)	[3]
Interest rate lock commitments [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	(12,000)	[3]
Interest rate lock commitments [Member] | Level 1 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[3]
Interest rate lock commitments [Member] | Level 2 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	0	[3]
Interest rate lock commitments [Member] | Level 3 [Member] | Recurring [Member]
Summary of Assets Measured at Fair Value on a Recurring Basis
Assets fair value	$ (12,000)	[3]

[1] Unrealized gains or losses on investments are recorded in accumulated other comprehensive income (loss) at each measurement date.

[2] Changes in the fair value of mortgage servicing rights are recognized in the current period earnings through net revenue.

[3] Gains or losses on derivatives are recognized in current period earnings through cost of sales.