Loans Receivable, Net - Text Tag (Details)	12 Months Ended
Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 5,700,000	$ 6,400,000
Financing Receivable, Modifications, Number of Contracts		0
FNMA & 3rd party loans excluded from financial statements	23,100,000	$ 25,700,000
Loans Pledged as Collateral	28,700,000
Loans Receivable, Individually Evaluated for Impairment	13,037,000	14,693,000
Allowance for Loan Losses, Individually Evaluated for Impairment	315,000	361,000
Loans Receivable, Impaired, Interest Lost on Nonaccrual Loans	324,000	$ 233,000
Loans 90 Days Past Due and Still Accruing	0		$ 0
Other non-performing asset	$ 1,100,000
Number of Real Estate Properties	8	8
Loans held-for-sale (HFS)	$ 0	$ 944,000
Modified Loan Subsequently Defaulted	0		0
Loans and Leases Receivable, Related Parties	$ 0	4,700,000
Loans and Leases Receivable, Related Parties, Additions	111,000
Loans and Leases Receivable, Related Parties, Proceeds	4,800,000
Business
Financing Receivable, Modifications [Line Items]
Overdrafts	35,000	76,000
Loans Receivable, Individually Evaluated for Impairment	3,289,000	4,087,000
Allowance for Loan Losses, Individually Evaluated for Impairment	95,000	41,000
Consumer
Financing Receivable, Modifications [Line Items]
Overdrafts	18,000	22,000
Loans Receivable, Individually Evaluated for Impairment	0	2,000
Allowance for Loan Losses, Individually Evaluated for Impairment	0	2,000
One-to-four family
Financing Receivable, Modifications [Line Items]
Loans Receivable, Individually Evaluated for Impairment	6,504,000	5,507,000
Allowance for Loan Losses, Individually Evaluated for Impairment	145,000	306,000
Non-performing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 1,900,000	$ 2,500,000
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 285,000

FNMA & 3rd party loans excluded from financial statements

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Other non-performing asset

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Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of financing receivables that have been modified by troubled debt restructurings.

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Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

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Recorded investment in financing receivables that are 90 days or more past due and still accruing.

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- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

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Reflects the amount of new advances made to related parties in the form of loan and lease receivables.

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Amount of cash inflow from related parties which reduce the amount of loans and leases receivable due from related parties.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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The face amount of loans that will be sold to other entities.

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- Definition

The number of real estate properties owned as of the balance sheet date.

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