Long-Term Debt (11.5% Senior Notes) (Details) (Secured debt [Member], 11.5% senior notes due 2017 [Member], USD $)	0 Months Ended
Mar. 28, 2012
Debt Instrument [Line Items]
Debt instrument, face amount	$ 225,000,000us-gaap_DebtInstrumentFaceAmount
Debt, unamortized discount	$ 8,300,000
Debt redemption price (percentage)	100.00%
Debt redemption price, change of control (percentage)	101.00%
Prior to May 15, 2015 [Member]
Debt Instrument [Line Items]
Debt redemption price (percentage)	111.50%
Debt redemption price, maximum percentage of principal amount redeemable (percent)	35.00%
On or After May 15, 2015 [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt redemption price (percentage)	100.00%
On or After May 15, 2015 [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt redemption price (percentage)	105.75%

Debt Instrument, Redemption Price, Maximum Percentage of Principal Amount Redeemable

No definition available.

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Namespace Prefix:	cvo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Redemption Price, Percentage, Change of Control

+ References

No definition available.

+ Details

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Namespace Prefix:	cvo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ 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

+ Details

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

- Details

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

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph e

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

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

- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

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

+ Details

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

- Details

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- Details

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