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Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	Apr. 29, 2011
MULTI CAP GROWTH TRUST (Prospectus Summary): \| MULTI CAP GROWTH TRUST
Risk/Return:	rr_RiskReturnAbstract
Risk/Return, Heading	rr_RiskReturnHeading	MULTI CAP GROWTH PORTFOLIO
Supplement Text	ck0000716716_SupplementTextBlock	Morgan Stanley October 4, 2011 Supplement SUPPLEMENT DATED OCTOBER 4, 2011 TO THE PROSPECTUSES OF MORGAN STANLEY VARIABLE INVESTMENT SERIES THE MULTI CAP GROWTH PORTFOLIO (the "Portfolio") CLASS X and CLASS Y Dated April 29, 2011
Investment Strategy, Heading	rr_StrategyHeading	The second sentence of the third paragraph under the section entitled "Portfolio Summary — Principal Investment Strategies" is deleted and replaced with the following:
Investment Strategy, Narrative	rr_StrategyNarrativeTextBlock	The Portfolio's use of derivatives may involve the purchase and sale of derivative instruments such as futures, options, swaps, structured investments and other related instruments and techniques.
SupplementClosingTextBlock	ck0000716716_Supplementclosingtextblock	PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.

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The date of the prospectus.

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Risk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicated

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Principal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.

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