Fair Value Measurements - Changes in Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Cash equivalents	$ 158,596	$ 72,993
Other Investments [Abstract]
Total assets measured at fair value	226,606	169,462
Sponsored funds
Investment securities - fair value
Marketable securities trading	40,191	50,614
Equity securities
Investment securities - fair value
Marketable securities trading	16,981	15,810
Trading debt securities
Investment securities - fair value
Marketable securities available for sale	2,099	2,677
Investment securities - available for sale
Other Investments [Abstract]
Investment securities - available for sale	2,023	20,662
Nonqualified retirement plan assets
Other Investments [Abstract]
Nonqualified retirement plan assets	6,716	6,706
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Cash equivalents	158,596	72,993
Other Investments [Abstract]
Total assets measured at fair value	222,484	146,123
Level 1 \| Sponsored funds
Investment securities - fair value
Marketable securities trading	40,191	50,614
Level 1 \| Equity securities
Investment securities - fair value
Marketable securities trading	16,981	15,810
Level 1 \| Trading debt securities
Investment securities - fair value
Marketable securities available for sale	0	0
Level 1 \| Investment securities - available for sale
Other Investments [Abstract]
Investment securities - available for sale	0	0
Level 1 \| Nonqualified retirement plan assets
Other Investments [Abstract]
Nonqualified retirement plan assets	6,716	6,706
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Cash equivalents	0	0
Other Investments [Abstract]
Total assets measured at fair value	0	18,900
Level 2 \| Sponsored funds
Investment securities - fair value
Marketable securities trading	0	0
Level 2 \| Equity securities
Investment securities - fair value
Marketable securities trading	0	0
Level 2 \| Trading debt securities
Investment securities - fair value
Marketable securities available for sale	0	0
Level 2 \| Investment securities - available for sale
Other Investments [Abstract]
Investment securities - available for sale	0	18,900
Level 2 \| Nonqualified retirement plan assets
Other Investments [Abstract]
Nonqualified retirement plan assets	0	0
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Cash equivalents	0	0
Other Investments [Abstract]
Total assets measured at fair value	4,122	4,439
Level 3 \| Sponsored funds
Investment securities - fair value
Marketable securities trading	0	0
Level 3 \| Equity securities
Investment securities - fair value
Marketable securities trading	0	0
Level 3 \| Trading debt securities
Investment securities - fair value
Marketable securities available for sale	2,099	2,677
Level 3 \| Investment securities - available for sale
Other Investments [Abstract]
Investment securities - available for sale	2,023	1,762
Level 3 \| Nonqualified retirement plan assets
Other Investments [Abstract]
Nonqualified retirement plan assets	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

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

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

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

- References

No definition available.

+ Details

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

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

Investments In Collateralized Loan Obligations

+ References

No definition available.

+ Details

Name:	vrts_InvestmentsInCollateralizedLoanObligations
Namespace Prefix:	vrts_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Investments In Nonqualified Retirement Plan Assets

+ References

No definition available.

+ Details

Name:	vrts_InvestmentsInNonqualifiedRetirementPlanAssets
Namespace Prefix:	vrts_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FinancialInstrumentAxis=vrts_SponsoredFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=vrts_TradingDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CollateralizedDebtObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=vrts_NonqualifiedRetirementPlanAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: