SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounts receivable (Details)	12 Months Ended
Dec. 31, 2021 customer
Accounts receivable
Number of products consigned to the customers	0

Represents the number of products which have been consigned to the customers.

No definition available.

Name:	rvp_NumberOfProductsConsignedToCustomer
Namespace Prefix:	rvp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration