v3.20.1

SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 28, 2020 | Dec. 28, 2019
Cost in excess of billings | $ 238,000 | $ 420,000
Retainage on contracts | $ 182,000 | $ 345,000
Minimum |  |
Payment terms number of days | 30 days |
Maximum |  |
Payment terms number of days | 90 days |

X
- Definition Amount of receivable reflecting the cost incurred on uncompleted contracts in excess of related billings. + References No definition available. + Details
Name: | cuo_CostInExcessOfBillings
Namespace Prefix: | cuo_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents payment terms in number of days after invoice is billed to the customer. + References No definition available. + Details
Name: | cuo_PaymentTermsNumberOfDays
Namespace Prefix: | cuo_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount billed to customers under long-term contracts or programs that have been withheld because of retainage provisions in a contract. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 910 -SubTopic 310 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118388040&loc=d3e49370-109356 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3(c)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_ContractReceivableRetainage
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |