Name:	cvd_CommittedMinimumVolumeArrangementsWithClientTermHighEndOfRange
Namespace Prefix:	cvd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the low end of the range of the contract term where the entity has committed minimum volume arrangements with certain clients, as given under revenue recognition.

No definition available.

Name:	cvd_CommittedMinimumVolumeArrangementsWithClientTermLowEndOfRange
Namespace Prefix:	cvd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the maximum duration of the contracts under which majority of the net revenues have been earned by the entity.

No definition available.

Name:	cvd_HistoricalStandardMaximumTermOfContractEarningsMajorityOfNetRevenues
Namespace Prefix:	cvd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The period of time between when revenue is recognized and when it is invoiced to the customer pursuant to contractual terms, high end of range (in years).

No definition available.

Name:	cvd_PeriodFromUnbilledReceivableToInvoicedHighEndOfRange
Namespace Prefix:	cvd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the potential duration of certain contracts under which net revenues have been earned by the entity.

No definition available.

Name:	cvd_PotentialDurationOfCertainContractsEarningNetRevenues
Namespace Prefix:	cvd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	cvd_TaxesAbstract
Namespace Prefix:	cvd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Carrying value as of the balance sheet date of obligations incurred and payable for non-income matters including value-added tax and state sales and use and other taxes. Used to reflect the current portion of the liabilities (due within one year).

No definition available.

Name:	cvd_TaxesPayableOtherThanIncomeTaxCurrent
Namespace Prefix:	cvd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The gross amount of unrecognized tax benefits including accrued interest pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.

No definition available.

Name:	cvd_UnrecognizedTaxBenefitsIncludingInterest
Namespace Prefix:	cvd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Example of the percentage of full contract value that is received as an upfront payment upon contract signing.

No definition available.

Name:	cvd_UpfrontPaymentExampleOfPercentageOfFullContractValue
Namespace Prefix:	cvd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

This element represents the amount of interest expense accrued as of the date of the statement of financial position for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 21

-Subparagraph c

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 15

-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.