Represents the contingent amount due to former shareholders.

No definition available.

Name:	rvp_ContingentLiabilityFormerShareholders
Namespace Prefix:	rvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cumulative and annual payments to previous shareholders.

+ References

No definition available.

+ Details

Name:	rvp_CumulativeAnnualPayments
Namespace Prefix:	rvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the number of former shareholders entitled to compensation.

+ References

No definition available.

+ Details

Name:	rvp_NumberOfEntitledShareholders
Namespace Prefix:	rvp_
Data Type:	xbrli:integerItemType
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_DividendsPayableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-SubTopic 405
-Topic 942
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481071/942-405-45-2

+ Details

Name:	us-gaap_DividendsPreferredStockCash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_StatementClassOfStockAxis=rvp_SeriesTwoThreeFourAndFiveConvertibleClassBPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_PreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=rvp_SeriesTwoConvertibleClassBPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=rvp_SeriesThreeConvertibleClassBPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

DIVIDENDS (Details)	1 Months Ended						3 Months Ended
DIVIDENDS (Details)	Apr. 30, 2024 USD ($)	Jan. 31, 2024 USD ($)	Oct. 31, 2023 USD ($)	Jul. 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2024 USD ($) stockholder
DIVIDENDS
Number of entitled shareholders \| stockholder							90
Contingent liability former shareholders							$ 1,400,000
Series II, III, IV and V Class B
DIVIDENDS
Cumulative amount of dividends						$ 5,056,945
Preferred Stock \| Series II, Class B
DIVIDENDS
Cash dividends paid	$ 39,050	$ 39,050	$ 39,050	$ 39,050	$ 39,050
Preferred Stock \| Series III, Class B
DIVIDENDS
Cash dividends paid	$ 18,561	$ 18,561	$ 19,061	$ 19,061	$ 19,061