Long Term Debt (Details Textual) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Dec. 31, 2011
Long term debt (Textual) [Abstract]
Agreement on Senior secured revolving credit facility	5 years
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Limitation for the issuance of standby letters of credit	$ 7.5
Long term debt (Textual) [Abstract]
Limitation for the issuance of standby letters of credit	7.5
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowing capacity	75.0
Provision conditioned by credit facility	50.0
Credit Facility amount outstanding	$ 15.0	$ 15.0
Credit Facility Interest Periods	1, 2, 3 or 6 months
Credit Facility Interest rate	2.00%
Acquisitions	less than 100% owned subsidiaries
Minimum percentage of owned subsidiaries	100.00%
Minimum interest coverage ratio	at least 4.00:1
Minimum percentage of interest adjustment	4.00%
Leverage ratio	no greater than 2.75:1
Maximum percentage of indebtedness	2.75%
Maximum [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Percentage of margin on principal amount	2.50%
Commitment fee	0.50%
Minimum [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Percentage of margin on principal amount	0.75%
Commitment fee	0.35%

Amount borrowed under the credit facility as of the balance sheet date.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for a specific purpose other than for financing goods acquired for inventory or imminent delivery to a customer.

+ References

No definition available.

+ Details

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

- Definition

The effective interest rate during the reporting period.

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

-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 19, 22

-Article 5

+ Details

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

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
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

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

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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

- Definition

Leverage ratio.

+ References

No definition available.

+ Details

Name:	vrts_LeverageRatio
Namespace Prefix:	vrts_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility amended term period.

+ References

No definition available.

+ Details

Name:	vrts_LineOfCreditFacilityAmendedTermPeriod
Namespace Prefix:	vrts_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility basis spread on alternate base rate.

+ References

No definition available.

+ Details

Name:	vrts_LineOfCreditFacilityBasisSpreadOnAlternateBaseRate
Namespace Prefix:	vrts_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility conditional provision for increase decrease.

+ References

No definition available.

+ Details

Name:	vrts_LineOfCreditFacilityConditionalProvisionForIncreaseDecrease
Namespace Prefix:	vrts_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility description of London Inter Bank offered rate.

+ References

No definition available.

+ Details

Name:	vrts_LineOfCreditFacilityDescriptionOfLondonInterBankOfferedRate
Namespace Prefix:	vrts_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	vrts_LongTermDebtTextualAbstract
Namespace Prefix:	vrts_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum leverage ratio.

+ References

No definition available.

+ Details

Name:	vrts_MaximumLeverageRatio
Namespace Prefix:	vrts_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum interest coverage ratio.

+ References

No definition available.

+ Details

Name:	vrts_MinimumInterestCoverageRatio
Namespace Prefix:	vrts_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum interest coverage ratio.

+ References

No definition available.

+ Details

Name:	vrts_MinimumInterestCoverageRatioOne
Namespace Prefix:	vrts_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Minority interest ownership percentage by parent description.

+ References

No definition available.

+ Details

Name:	vrts_MinorityInterestOwnershipPercentageByParentDescription
Namespace Prefix:	vrts_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration