EARNINGS PER SHARE (Details) - $ / shares	3 Months Ended	9 Months Ended
Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
EARNINGS PER SHARE
Difference between the calculation of basic and diluted EPS (in dollars per share)	$ 0	$ 0	$ 0	$ 0

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