EARNINGS PER SHARE (Details) - $ / shares	3 Months Ended
Mar. 28, 2020	Mar. 30, 2019
EARNINGS PER SHARE
Difference between the calculation of basic and diluted EPS (in dollars per share)	$ 0.00	$ 0.00

Represents the difference between per share amount of basic and diluted earnings due to outstanding common stock equivalents, warrants or other convertible securities.

No definition available.

Name:	cuo_DifferenceBetweenEarningPerShareBasicAndDiluted
Namespace Prefix:	cuo_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration