SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Self-insured employee benefit costs (Details)	Mar. 31, 2024 USD ($)
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Self-insured threshold for individual claims	$ 100,000
Self-insured threshold for total plain claims for the year	$ 1,700,000

The threshold amount of self-insurance for health insurance benefit liability for total plan claims for the year assumed by the Company.

No definition available.

Name:	rvp_HealthInsuranceBenefitsSelfInsuranceThresholdForTotalPlanClaims
Namespace Prefix:	rvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant