LOANS RECEIVABLE - Additional information (Details) - USD ($) $ in Thousands	6 Months Ended
Sep. 30, 2019	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred loan fees	$ 4,100	$ 4,000
Discount on Loans receivable	1,300	1,500
Premiums on Loans receivable	1,600	1,800
Loans pledged as collateral	$ 502,400
Percentage of loans and extensions of credit outstanding	15.00%
Total loans	$ 881,316	876,116
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	88,645	92,409
Automobile Loan [Member] \| Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 3,400	$ 5,800

Represents the amount related to discounts on loans receivable.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represent percentage of loans and extensions of credit outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	rvsb_
Data Type:	num:percentItemType
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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
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-Section 50
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
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+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Disclosure of the unamortized amount of the premium on the note or receivable which is added to the face amount of the receivable or loan. The discount or premium is defined as the difference between the present value and the face amount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

+ Details

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- Details

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- Details

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