Segment Information (Details) - Schedule of sales by product type - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Optical [Member]
Segment Information (Details) - Schedule of sales by product type [Line Items]
Total revenue	$ 1,302	$ 892	$ 2,646	$ 3,008

Amount of revenues recognized from goods sold, services rendered, insurances premium, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenues, and sales and trading gain (loss).

No definition available.

Name:	rbcn_Revenue
Namespace Prefix:	rbcn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration