Name:	cas_EarningsBeforeInterestTaxesDepreciationAndAmortizationToFixedChargesRatio
Namespace Prefix:	cas_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

The lower bound of excess revolver availability as defined in Revolving Credit Facility Agreement, under which amount the Company must retain a ratio of EBITDA to fixed charged of 1.1 to 1.0.

No definition available.

Name:	cas_ExcessAvailabilityLowerBoundSpringingCovenant
Namespace Prefix:	cas_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Excess availability of revolving credit facility.

No definition available.

Name:	cas_ExcessAvailabilityOfRevolvingCreditFacility
Namespace Prefix:	cas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Percentage of excess availability to calculated borrowing base, under which percentage certain springing covenants occur.

No definition available.

Name:	cas_ExcessAvailabilityToBorrowingBasePercentage
Namespace Prefix:	cas_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The upper bound of excess revolver availability under which amount the lender has the right to take full dominion of the Company's cash collections and apply them to outstanding loans under the Revolving Credit Agreement.

No definition available.

Name:	cas_ExcessAvailabilityUpperBoundSpringingCovenant
Namespace Prefix:	cas_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of debt outstanding by type or by instrument at that time.

No definition available.