Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

+ Details

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

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
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.

+ References

No definition available.

+ 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

+ Details

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

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfLongTermLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt Instrument, Amount Required To Be Prepaid, Percent of Excess Cash Flow

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Annual Principal Payment, Percentage of Principal

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Basis Spread On Variable Rate, Reduction In Rate

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Basis Spread on Variable Rate, Floor

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Potential Reduction To Basis Spread On Variable Rate, Pro Forma Leverage Ratio Used For Calculation

+ References

No definition available.

+ Details

Name:	vrts_DebtInstrumentPotentialReductionToBasisSpreadOnVariableRateProFormaLeverageRatioUsedForCalculation
Namespace Prefix:	vrts_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Premium Due If Prepaid In Connection With Repricing Transaction Within Six Months Of Credit Agreement Closing

+ References

No definition available.

+ Details

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

- Definition

Line of Credit Facility, Covenant Terms, Leverage Ratio

+ References

No definition available.

+ Details

Name:	vrts_LineofCreditFacilityCovenantTermsLeverageRatio
Namespace Prefix:	vrts_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Covenant Terms, Percent Of Aggregate Revolving Commitments

+ References

No definition available.

+ Details

Name:	vrts_LineofCreditFacilityCovenantTermsPercentOfAggregateRevolvingCommitments
Namespace Prefix:	vrts_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=vrts_CreditFacility2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=vrts_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=vrts_CreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=vrts_AdditionalTermLoan2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	vrts_LeverageRatioScenarioAxis=vrts_LeverageRatioBelow1.00Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	vrts_LeverageRatioScenarioAxis=vrts_LeverageRatioBelow0.50Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Narrative (Details)		12 Months Ended
Debt - Narrative (Details)	Feb. 15, 2018	Dec. 31, 2020 USD ($)	Jun. 01, 2017 USD ($)
Credit Facility 2017 \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable interest rate	2.50%
Reduction in rate	2500.00%
Potential reduction to basis spread on variable rate, pro forma leverage ratio used for calculation	1.00
Credit Facility 2017 \| Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable interest rate	1.50%
Term Loan \| Credit Facility 2017
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 365,000,000.0
Amount outstanding		$ 205,700,000
Debt issuance costs		$ 4,500,000
Annual principal payment, percentage of principal		1.00%
Amount required to be prepaid, percent of excess cash flow		50.00%
Premium due if prepaid in connection with repricing transaction within six months of credit agreement closing		1.00%
Term Loan \| Credit Facility 2017 \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate, floor	0.75%
Term Loan \| Credit Agreement
Line of Credit Facility [Line Items]
Debt term		7 years
Principal loan payments		$ 80,100,000
Debt retired		10,000,000.0
Amount paid for debt		$ 8,900,000
Term Loan \| Additional Term Loan 2018
Line of Credit Facility [Line Items]
Covenant terms, leverage ratio	2.50
Covenant terms, percent of aggregate revolving commitments	30.00%
Revolving Credit Facility \| Credit Facility 2017
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 100,000,000.0
Revolving Credit Facility \| Credit Facility 2017 \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate, floor	0.00%
Revolving Credit Facility \| Credit Agreement
Line of Credit Facility [Line Items]
Debt term		5 years
Amount outstanding		$ 0
Leverage Ratio Below 1.00 \| Term Loan \| Credit Facility 2017
Line of Credit Facility [Line Items]
Amount required to be prepaid, percent of excess cash flow		25.00%
Leverage Ratio Below 0.50 \| Term Loan \| Credit Facility 2017
Line of Credit Facility [Line Items]
Amount required to be prepaid, percent of excess cash flow		0.00%