Consolidated Subsidiary, Ownership Percentage

No definition available.

Name:	cas_ConsolidatedSubsidiaryOwnershipPercentage
Namespace Prefix:	cas_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

As of the balance sheet date, the amount of excess cash flow, as defined by the indenture agreement, required to be offered for the purpose of purchasing outstanding Senior Secured Notes

+ References

No definition available.

+ Details

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

- Definition

The amount of the redemption price in percentage in the event of excess cash flow.

+ References

No definition available.

+ Details

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

- Definition

Amount of outstanding principal due for the Senior Secured Notes at the maturity date, before deducting unamortized discount.

+ References

No definition available.

+ Details

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

- Definition

Timeframe after the end of each fiscal year that the Company must make an offer to purchase New Secured Notes with certain of its excess cash flow for such fiscal year. Days After Fiscal Year End

+ References

No definition available.

+ Details

Name:	cas_TimeframeAfterEndOfEachFiscalYearThatCompanyMustMakeOfferToPurchaseNewSecuredNotesWithCertainOfItsExcessCashFlowForSuchFiscalYearDaysAfterFiscalYearEnd
Namespace Prefix:	cas_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Debt Secured Notes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 15, 2011
Debt Instrument [Line Items]
Senior Secured Notes Principal Amount	$ 210,000	$ 210,000
Senior Secured Notes Due in 2016 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount		15,000
Maturity date	Dec. 15, 2016
Stated interest rate on debt			12.75%
Timeframe after the end of each fiscal year that the Company must make an offer to purchase New Secured Notes with certain of its excess cash flow for such fiscal year. Days After Fiscal Year End	95 days
Redemption Price, Stated as a Percentage of Principal, Percentage, Excess Cash Flow	103.00%
Excess cash flow, Secured Notes Indebture Agreement		$ 0
Domestic Subsidiaries [Member]
Debt Instrument [Line Items]
Consolidated Subsidiary, Ownership Percentage	100.00%