LOANS RECEIVABLE - Additional information (Details)	12 Months Ended
Mar. 31, 2023 USD ($) item	Mar. 31, 2022 USD ($) item
LOANS RECEIVABLE
Deferred loan fees	$ 4,400,000	$ 4,500,000
Number of Loans to Foreign Domiciled Businesses or Foreign Countries \| item	0	0
Discount on Loans receivable	$ 1,400,000	$ 371,000
Premiums On Loans Receivable.	2,100,000	$ 2,400,000
Loans pledged as collateral	$ 993,547,000
Percentage of loans and extensions of credit outstanding	15.00%
Asset Pledged as Collateral \| FHLB and FRB Borrowing Arrangements
LOANS RECEIVABLE
Loans pledged as collateral	$ 601,500,000
Raw Land Loans [Member] \| Commercial Real Estate Portfolio Segment
LOANS RECEIVABLE
Maximum loan-to-value ratio	65.00%
Land and Land Improvements [Member] \| Commercial Real Estate Portfolio Segment
LOANS RECEIVABLE
Maximum loan-to-value ratio	75.00%
Real estate one-to-four family \| Consumer
LOANS RECEIVABLE
Maximum loan-to-value ratio	80.00%
Real estate one-to-four family \| Consumer \| Minimum
LOANS RECEIVABLE
Terms of maturity	15 years
Real estate one-to-four family \| Consumer \| Maximum
LOANS RECEIVABLE
Terms of maturity	30 years
Commercial Real Estate \| Commercial Real Estate Portfolio Segment \| Minimum
LOANS RECEIVABLE
Maximum loan-to-value ratio	65.00%
Commercial Real Estate \| Commercial Real Estate Portfolio Segment \| Maximum
LOANS RECEIVABLE
Maximum loan-to-value ratio	80.00%

Represents the amount related to discounts on loans receivable.

No definition available.

Name:	rvsb_DiscountOnLoansReceivable
Namespace Prefix:	rvsb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	rvsb_FinancingReceivableExcludingAccruedInterestDeferredIncome
Namespace Prefix:	rvsb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Loans Receivable Terms Of Maturity.

+ References

No definition available.

+ Details

Name:	rvsb_LoansReceivableTermsOfMaturity
Namespace Prefix:	rvsb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

maximum loan-to-value ratio.

+ References

No definition available.

+ Details

Name:	rvsb_MaximumLoanToValueRatio
Namespace Prefix:	rvsb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of loans to foreign domiciled businesses or foreign countries.

+ References

No definition available.

+ Details

Name:	rvsb_NumberOfLoansToForeignDomiciledBusinessesOrForeignCountries
Namespace Prefix:	rvsb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represent percentage of loans and extensions of credit outstanding.

+ References

No definition available.

+ Details

Name:	rvsb_PercentageOfLoansAndExtensionsOfCreditOutstanding
Namespace Prefix:	rvsb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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

Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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 https://asc.fasb.org/extlink&oid=124435984&loc=d3e28541-108399

+ Details

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

- Details

Name:	us-gaap_PledgedStatusAxis=us-gaap_AssetPledgedAsCollateralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PledgingPurposeAxis=rvsb_FederalHomeLoanBankAndFederalReserveBankBorrowingArrangementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rvsb_RawLandLoansMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_LandAndLandImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=rvsb_RealEstateOneToFourFamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
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