Amount borrowed under the asset securitization facility as of the balance sheet date

Name:	cvg_AccountsReceivableSecuritization
Namespace Prefix:	cvg
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Borrowing capacity under the asset securitization facility secured by accounts receivable.

+ Details

Name:	cvg_AssetSecuritizationFacility
Namespace Prefix:	cvg
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects when the asset securitization facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ Details

Name:	cvg_AssetSecuritizationFacilityExpirationDate
Namespace Prefix:	cvg
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contingent purchase price obligation.

+ Details

Name:	cvg_ContingentPurchasePriceObligation
Namespace Prefix:	cvg
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lease term of capital lease obligation.

+ Details

Name:	cvg_LeaseTerm
Namespace Prefix:	cvg
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Residual value guaranteed to lessor from company.

+ Details

Name:	cvg_ResidualValueGuaranteedToLessorFromCompany
Namespace Prefix:	cvg
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 16

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6455398&loc=d3e45280-112737

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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.

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The date upon which a lease or a group of leases is set to expire.

+ Details

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Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 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)

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

+ Details

Name:	us-gaap_OtherLongTermDebt
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt And Capital Lease Obligations (Other) (Details) (USD $) In Millions	9 Months Ended				12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009	Dec. 31, 2009 Asset Securitization Facility Expire in 2010 [Member]	Dec. 31, 2009 Asset Securitization Facility Expire in 2012 [Member]
Debt Instrument
Asset Securitization Facility	$ 150.0			$ 125.0	$ 50.0	$ 75.0
Asset Securitization Facility, Expiration Date	June 2014				June 2010	June 2012
Accounts Receivable Securitization	0	85.0
Lease Expiration Date	June 2010
Lease term	5 years
Contingent Purchase Price Obligation	55.0
Residual Value Guaranteed To Lessor From Company	47.0
Capital Lease Obligations	59.1	58.0	55.0
Other Long-term Debt	$ 11.0	$ 10.7