Debt (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended
Jan. 31, 2013
Credit Agreement
Debt
Maximum borrowing capacity	18.6
Credit Agreement \| Minimum
Debt
Fixed charge coverage ratio to be maintained	1.2
Credit Agreement \| Maximum
Debt
Senior funded debt ratio	2.0
Term Loan
Debt
Principal amount	16.6
Upfront fee	0.07
Term Loan \| November 20, 2012 to February 28, 2013
Debt
Equal monthly installments for repayment of loan	0.65
Term Loan \| Thereafter through August 31, 2017
Debt
Equal monthly installments for repayment of loan	0.89
Term Loan \| Adjusted annual LIBOR
Debt
Variable rate basis	Adjusted annual LIBOR
Interest rate added to the reference rate (as a percent)	2.75%
Term Loan \| Prime rate
Debt
Variable rate basis	Prime rate
Interest rate subtracted from the reference rate (as a percent)	0.25%
Term Loan \| 1 month LIBOR \| Minimum
Debt
Variable rate basis	1 month LIBOR
Interest rate added to the reference rate (as a percent)	2.50%
Revolving line of credit
Debt
Maximum borrowing capacity	2.0
Monthly non-usage fee percentage	0.25%
Revolving line of credit \| Adjusted annual LIBOR
Debt
Variable rate basis	Adjusted annual LIBOR
Interest rate added to the reference rate (as a percent)	2.25%
Revolving line of credit \| Prime rate
Debt
Variable rate basis	Prime rate
Interest rate subtracted from the reference rate (as a percent)	0.25%
Revolving line of credit \| 1 month LIBOR \| Minimum
Debt
Variable rate basis	1 month LIBOR
Interest rate added to the reference rate (as a percent)	2.50%

The percentage points subtracted from the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	chke_DebtInstrumentBasisReductionInVariableRate
Namespace Prefix:	chke_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the fixed charge coverage ratio to be maintained under the financial covenant.

+ References

No definition available.

+ Details

Name:	chke_DebtInstrumentCovenantFixedChargeCoverageRatio
Namespace Prefix:	chke_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the senior funded debt ratio to be maintained under the financial covenant.

+ References

No definition available.

+ Details

Name:	chke_DebtInstrumentCovenantSeniorFundedDebtRatio
Namespace Prefix:	chke_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

+ 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(b))

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

+ Details

Name:	us-gaap_DebtInstrumentFeeAmount
Namespace Prefix:	us-gaap_
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

- Definition

Amount of the required periodic payments applied to principal.

+ 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)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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 210.5-02.19(b),22(b))

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

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration