The original issue discount percentage of the full principal amount of the senior secured term loan credit facilities.

No definition available.

Name:	casl_DebtInstrumentTermLoanDiscountRatePercentage
Namespace Prefix:	casl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Portion of Delayed Draw Facility that was avaiable and borrowed in December 2016.

+ References

No definition available.

+ Details

Name:	casl_DelayedDrawFacility2016Amount
Namespace Prefix:	casl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Portion of Delayed Draw Facility that becomes available in June 2017.

+ References

No definition available.

+ Details

Name:	casl_DelayedDrawFacilityJune2017Amount
Namespace Prefix:	casl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total amount of Delayed Draw Facility.

+ References

No definition available.

+ Details

Name:	casl_DelayedDrawFacilityTotal
Namespace Prefix:	casl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum consolidated liquidity, as defined by the Credit Facilities agreement, that the Company is required to maintain.

+ References

No definition available.

+ Details

Name:	casl_MinimumConsolidatedLiquidity
Namespace Prefix:	casl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Total aggregate principal amount of Senior Secured Term Loan Credit Facility available.

+ References

No definition available.

+ Details

Name:	casl_SecuredTermLoanCreditFacilityTotalAvailable
Namespace Prefix:	casl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Term Loan Facility Initial Funding

+ References

No definition available.

+ Details

Name:	casl_TermLoanFacilityInitialFunding
Namespace Prefix:	casl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

Reference 1: 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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ 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 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

Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=casl_SeniorSecuredTermLoanCreditFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=casl_WarrantswithExercisePriceof0.50PerShareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=casl_WarrantswithExercisePriceof0.65PerShareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt Senior Secured Term Loan Credit Facilities (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 08, 2016
Debt Instrument [Line Items]
Restricted Cash and Cash Equivalents, Noncurrent	$ 7,923	$ 7,968
Class of Warrant or Right, Outstanding	5,000
Senior Secured Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Secured Term Loan Credit Facility, Total Available			$ 112,000
Term Loan Facility Initial Funding			75,000
Delayed Draw Facility, Total			$ 37,000
Delayed Draw Facility, 2016 Amount		$ 24,500
Delayed Draw Facility, June 2017 Amount	$ 12,500
Debt Instrument, Term Loan, Discount Rate, Percentage	3.00%
Debt Instrument, Interest Rate, Stated Percentage	11.00%
Debt Instrument, Maturity Date	Sep. 14, 2018
Minimum Consolidated Liquidity	$ 20,000
Warrants with Exercise Price of $0.50 Per Share [Member]
Debt Instrument [Line Items]
Class of Warrant or Right, Outstanding	2,500
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.50
Warrants with Exercise Price of $0.65 Per Share [Member]
Debt Instrument [Line Items]
Class of Warrant or Right, Outstanding	2,500
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.65