Weighted Average Amortization Period

Name:	cvg_WeightedAverageAmortizationPeriod
Namespace Prefix:	cvg
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of intangible assets over their estimated remaining economic lives.

+ Details

Name:	us-gaap_AdjustmentForAmortization
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 45
-Subparagraph a(1)

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The useful life of all finite-lived intangible assets. This may be stated as a fixed number (for example, 10 years) if all assets have the same useful life, or it can be stated in a range (for example, six to eight years) if there is a range of useful lives in the asset group.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 12, 13, 14

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsUsefulLife
Namespace Prefix:	us-gaap
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMaximum
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsUsefulLifeMinimum
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 43

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The change during the reporting period in the carrying value of goodwill. The change could be the result of new goodwill acquired, goodwill impairment during the period, goodwill written off related to the sale of a business or other adjustments to goodwill.

+ Details

Name:	us-gaap_GoodwillPeriodIncreaseDecrease
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The average useful life of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land and improvements, buildings, and production equipment.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLifeAverage
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

Goodwill And Other Intangible Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 years	Jun. 30, 2010	Dec. 31, 2011	Dec. 31, 2010
Goodwill, net	$ 820.7		$ 820.7			$ 820.5
Reduction to goodwill			2.2
Intangible assets	60.7		60.7			69.1
Weighted average amortization period			5.9
Amortization expense	2.4	2.6	4.8	5.2	10.0
Software [Member]
Intangible assets	25.8		25.8
Intangible assets, useful life, minimum			5
Intangible assets, useful life, maximum			8
Weighted average depreciation period			4.5
Trademarks [Member]
Intangible assets	2.9		2.9
Trademarks, useful life			4
Customer Relationships And Other Intangibles [Member]
Intangible assets	$ 32.0		$ 32.0
Intangible assets, useful life, minimum			7
Intangible assets, useful life, maximum			12