FAIR VALUE MEASUREMENTS (Details) $ in Thousands	Sep. 28, 2019 USD ($)
Fair Value Measurements
Fair value, financial instruments transferred between levels	$ 0

Amount of transfers of financial instruments measured on a recurring basis between all the levels of hierarchy.

No definition available.

Name:	cuo_FairValueMeasurementTransfersBetweenLevels
Namespace Prefix:	cuo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant