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Objective, Primary [Text Block]

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Risk/Return [Heading]

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Morgan Stanley Multi Cap Growth Trust

Objective [Heading]

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Investment Objective

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Morgan Stanley Multi Cap Growth Trust (the "Fund") seeks long-term capital appreciation.

Expense [Heading]

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Fees and Expenses

Expense Narrative [Text Block]

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The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the Morgan Stanley Funds. More information about these and other discounts is available from your financial advisor and in the "Share Class Arrangements" section beginning on page 25 of this Prospectus and in the "Purchase, Redemption and Pricing of Shares" section beginning on page 50 of the Fund's Statement of Additional Information ("SAI").

Shareholder Fees Caption [Text]

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Shareholder Fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

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Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in Total Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 43% of the average value of its portfolio.

Portfolio Turnover, Rate

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43.00%

Expense Breakpoint Discounts [Text]

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You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the Morgan Stanley Funds.

Expense Breakpoint, Minimum Investment Required [Amount]

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$ 25,000

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The example assumes that you invest $10,000 in the Fund, your investment has a 5% return each year, and the Fund's operating expenses remain the same (except for the ten-year amounts for Class B shares which reflect the conversion to Class A shares eight years after the end of the calendar month in which the shares were purchased). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

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If You SOLD Your Shares:

Expense Example, No Redemption, By Year, Caption [Text]

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If You HELD Your Shares:

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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The Fund will normally invest at least 65% of its assets in a portfolio of common stocks of companies with market capitalizations, at the time of purchase, within the capitalization range of the companies comprising the Russell 3000® Growth Index, which as of December 31, 2012 was between $28 million and $500 billion. The Fund's "Adviser," Morgan Stanley Investment Management Inc., seeks long-term capital appreciation by investing primarily in established and emerging companies. The Adviser emphasizes a bottom-up stock selection process, seeking attractive investments on an individual company basis. In selecting securities for investment, the Adviser seeks to invest in high quality companies it believes have sustainable competitive advantages and the ability to redeploy capital at high rates of return. The Adviser typically favors companies with rising returns on invested capital, above average business visibility, strong free cash flow generation and an attractive risk/reward. The Fund's investments in equity securities may include convertible securities. The Fund may, but it is not required to, use derivative instruments as discussed herein. These derivative instruments will be counted toward the Fund's 65% policy discussed above to the extent they have economic characteristics similar to the securities included within that policy.

The Fund may invest up to 25% of its net assets in foreign securities, including emerging market securities, and securities classified as American Depositary Receipts ("ADRs"), Global Depositary Receipts ("GDRs"), American Depositary Shares ("ADSs") or Global Depositary Shares ("GDSs"), foreign U.S. dollar-denominated securities that are traded on a U.S. exchange or local shares of non-U.S. issuers. The Fund may utilize foreign currency forward exchange contracts, which are derivatives, in connection with its investments in foreign securities. The Fund may invest in privately placed and restricted securities.

Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

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There is no assurance that the Fund will achieve its investment objective and you can lose money investing in this Fund. The principal risks of investing in the Fund include:

• Common Stock and Other Equity Securities. In general, common stock and other equity security values fluctuate, and sometimes widely fluctuate, in response to activities specific to the issuer of the security as well as factors unrelated to the fundamental condition of the issuer, including general market, economic and political conditions. To the extent that the Fund invests in convertible securities, and the convertible security's investment value is greater than its conversion value, its price will be likely to increase when interest rates fall and decrease when interest rates rise. If the conversion value exceeds the investment value, the price of the convertible security will tend to fluctuate directly with the price of the underlying equity security.

• Small and Medium Capitalization Companies. Investments in small and medium capitalization companies may involve greater risks than investments in larger, more established companies. The securities issued by small and medium capitalization companies may be less liquid, and such companies may have more limited markets, financial resources and product lines, and may lack the depth of management of larger companies.

• Foreign and Emerging Market Securities. Investments in foreign markets entail special risks such as currency, political, economic and market risks. There also may be greater market volatility, less reliable financial information, higher transaction and custody costs, decreased market liquidity and less government and exchange regulation associated with investments in foreign markets. In addition, investments in certain foreign markets, which have historically been considered stable, may become more volatile and subject to increased risk due to ongoing developments and changing conditions in such markets. Moreover, the growing interconnectivity of global economies and financial markets has increased the probability that adverse developments and conditions in one country or region will affect the stability of economies and financial markets in other countries or regions. The risks of investing in emerging market countries are greater than risks associated with investments in foreign developed countries. In addition, the Fund's investments may be denominated in foreign currencies and therefore, to the extent unhedged, the value of the investment will fluctuate with the U.S. dollar exchange rates. To the extent hedged by use of foreign currency forward exchange contracts, the precise matching of foreign currency forward exchange contract amounts and the value of the securities involved will not generally be possible because the future value of such securities in foreign currencies will change as a consequence of market movements in the value of those securities between the date on which the contract is entered into and the date it matures. There is additional risk that such transactions reduce or preclude the opportunity for gain if the value of the currency should move in the direction opposite to the position taken and that foreign currency forward exchange contracts create exposure to currencies in which the Fund's securities are not denominated. The use of foreign currency forward exchange contracts involves the risk of loss from the insolvency or bankruptcy of the counterparty to the contract or the failure of the counterparty to make payments or otherwise comply with the terms of the contract.

• Privately Placed and Restricted Securities. The Fund's investments may also include privately placed securities, which are subject to resale restrictions. These securities will have the effect of increasing the level of Fund illiquidity to the extent the Fund may be unable to sell or transfer these securities due to restrictions on transfers or on the ability to find buyers interested in purchasing the securities. The illiquidity of the market, as well as the lack of publicly available information regarding these securities, may also adversely affect the ability to arrive at a fair value for certain securities at certain times.

Shares of the Fund are not bank deposits and are not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

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There is no assurance that the Fund will achieve its investment objective and you can lose money investing in this Fund.

Risk Not Insured Depository Institution [Text]

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Shares of the Fund are not bank deposits and are not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

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Past Performance

Performance Narrative [Text Block]

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The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's Class A shares' performance from year-to-year and by showing how the Fund's average annual returns for the one, five and 10 year periods compare with those of a broad measure of market performance, as well as an index that represents a group of similar mutual funds, over time. The performance of other Classes will differ because the Classes have different ongoing fees. The performance information in the bar chart does not reflect the deduction of sales charges; if these amounts were reflected, returns would be less than shown. The Fund's returns in the table include the maximum applicable sales charge for each Class and assume you sold your shares at the end of each period (unless otherwise noted). The Fund's past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available online at www.morganstanley.com/im or by calling toll-free (800) 869-NEWS.

Performance Information Illustrates Variability of Returns [Text]

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Performance Additional Market Index [Text]

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The Russell 3000 Growth Index measures the performance of the broad growth segment of the U.S. equity universe. It includes those Russell 3000 Index companies with higher price-to-book ratios and higher forecasted growth values. The Russell 3000 Index measures the performance of the largest 3000 U.S. companies representing approximately 98% of the investable U.S. equity market. It is not possible to invest directly in an index. The Lipper Multi-Cap Growth Funds Index is an equally weighted performance index of the largest qualifying funds (based on net assets) in the Lipper Multi-Cap Growth Funds classification. There are currently 30 funds represented in this Index.

Performance Availability Phone [Text]

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(800) 869-NEWS

Performance Availability Website Address [Text]

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www.morganstanley.com/im

Performance Past Does Not Indicate Future [Text]

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The Fund's past performance (before and after taxes) does not indicate how the Fund will perform in the future.

Bar Chart [Heading]

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Annual Total Returns-Calendar Years*

Bar Chart Does Not Reflect Sales Loads [Text]

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The performance information in the bar chart does not reflect the deduction of sales charges; if these amounts were reflected, returns would be less than shown.

Bar Chart Footnotes [Text Block]

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* The Fund previously disclosed the total return of Class B shares. However, Class B shares are closed to new investments. The bar chart now shows Class A shares which remain open to new investments.

Bar Chart Closing [Text Block]

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High Quarter				6/30/09					22.71	%
Low Quarter				12/31/08					–31.49	%

Bar Chart, Reason Selected Class Different from Immediately Preceding Period [Text]

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The Fund previously disclosed the total return of Class B shares. However, Class B shares are closed to new investments. The bar chart now shows Class A shares which remain open to new investments.

Highest Quarterly Return, Label

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High Quarter

Highest Quarterly Return, Date

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Jun. 30, 2009

Highest Quarterly Return

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22.71%

Lowest Quarterly Return, Label

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Low Quarter

Lowest Quarterly Return, Date

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Dec. 31, 2008

Lowest Quarterly Return

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(31.49%)

Performance Table Does Reflect Sales Loads

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The Fund's returns in the table include the maximum applicable sales charge for each Class and assume you sold your shares at the end of each period (unless otherwise noted).

Index No Deduction for Fees, Expenses, Taxes [Text]

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(reflects no deduction for fees, expenses or taxes)

Performance Table Uses Highest Federal Rate

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Performance Table Not Relevant to Tax Deferred

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Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

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After-tax returns for the Fund's other Classes will vary from the Class A shares' returns.

Performance Table Explanation after Tax Higher

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After-tax returns may be higher than before-tax returns due to foreign tax credits and/or an assumed benefit from capital losses that would have been realized had Fund shares been sold at the end of the relevant periods, as applicable.

Performance Table Closing [Text Block]

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The after-tax returns shown in the table above are calculated using the historical highest individual federal marginal income tax rates during the period shown and do not reflect the impact of state and local taxes. After-tax returns for the Fund's other Classes will vary from the Class A shares' returns. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns may be higher than before-tax returns due to foreign tax credits and/or an assumed benefit from capital losses that would have been realized had Fund shares been sold at the end of the relevant periods, as applicable.

Caption

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Average Annual Total Returns For Periods Ended December 31, 2012

Russell 3000® Growth Index (reflects no deduction for fees, expenses or taxes)2

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rr_AverageAnnualReturnYear01

15.21%

^[1]

rr_AverageAnnualReturnYear05

3.15%

^[1]

rr_AverageAnnualReturnYear10

7.69%

^[1]

Lipper Multi-Cap Growth Funds Index (reflects no deduction for taxes)3

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rr_AverageAnnualReturnYear01

15.88%

^[2]

rr_AverageAnnualReturnYear05

1.41%

^[2]

rr_AverageAnnualReturnYear10

8.06%

^[2]

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

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5.25%

Maximum deferred sales charge (load) (as a percentage based on the lesser of the offering price or net asset value at redemption)

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none

^[3]

Distribution and/or Shareholder Service (12b-1) Fee

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0.67%

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0.25%

^[4]

rr_OtherExpensesOverAssets

0.38%

rr_ExpensesOverAssets

1.30%

rr_ExpenseExampleYear01

650

rr_ExpenseExampleYear03

915

rr_ExpenseExampleYear05

1,200

rr_ExpenseExampleYear10

2,010

rr_ExpenseExampleNoRedemptionYear01

650

rr_ExpenseExampleNoRedemptionYear03

915

rr_ExpenseExampleNoRedemptionYear05

1,200

rr_ExpenseExampleNoRedemptionYear10

2,010

Annual Return 2003

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41.10%

Annual Return 2004

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22.43%

Annual Return 2005

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22.10%

Annual Return 2006

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7.21%

Annual Return 2007

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18.82%

Annual Return 2008

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(48.66%)

Annual Return 2009

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69.96%

Annual Return 2010

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26.90%

Annual Return 2011

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(7.80%)

Annual Return 2012

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12.20%

rr_AverageAnnualReturnYear01

6.31%

rr_AverageAnnualReturnYear05

1.65%

rr_AverageAnnualReturnYear10

11.30%

A | After Taxes on Distributions

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rr_AverageAnnualReturnYear01

4.40%

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rr_AverageAnnualReturnYear05

1.29%

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rr_AverageAnnualReturnYear10

11.10%

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A | After Taxes on Distributions and Sale of Fund Shares

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rr_AverageAnnualReturnYear01

6.58%

rr_AverageAnnualReturnYear05

1.41%

rr_AverageAnnualReturnYear10

10.14%

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

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none

Maximum deferred sales charge (load) (as a percentage based on the lesser of the offering price or net asset value at redemption)

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5.00%

^[6]

Distribution and/or Shareholder Service (12b-1) Fee

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0.67%

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1.00%

^[4]

rr_OtherExpensesOverAssets

0.38%

rr_ExpensesOverAssets

2.05%

rr_ExpenseExampleYear01

708

rr_ExpenseExampleYear03

943

rr_ExpenseExampleYear05

1,303

rr_ExpenseExampleYear10

2,187

rr_ExpenseExampleNoRedemptionYear01

208

rr_ExpenseExampleNoRedemptionYear03

643

rr_ExpenseExampleNoRedemptionYear05

1,103

rr_ExpenseExampleNoRedemptionYear10

2,187

rr_AverageAnnualReturnYear01

6.57%

rr_AverageAnnualReturnYear05

1.63%

rr_AverageAnnualReturnYear10

11.21%

^[7]

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

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none

^[8]

Maximum deferred sales charge (load) (as a percentage based on the lesser of the offering price or net asset value at redemption)

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none

^[8]

Distribution and/or Shareholder Service (12b-1) Fee

rr_ManagementFeesOverAssets

0.67%

^[8]

rr_DistributionAndService12b1FeesOverAssets

0.75%

^[4],[8]

rr_OtherExpensesOverAssets

0.38%

^[8]

rr_ExpensesOverAssets

1.80%

^[8]

rr_ExpenseExampleYear01

183

^[8]

rr_ExpenseExampleYear03

566

^[8]

rr_ExpenseExampleYear05

975

^[8]

rr_ExpenseExampleYear10

2,116

^[8]

rr_ExpenseExampleNoRedemptionYear01

183

^[8]

rr_ExpenseExampleNoRedemptionYear03

566

^[8]

rr_ExpenseExampleNoRedemptionYear05

975

^[8]

rr_ExpenseExampleNoRedemptionYear10

2,116

^[8]

rr_AverageAnnualReturnYear01

10.43%

^[9]

rr_AverageAnnualReturnYear05

1.99%

^[9]

rr_AverageAnnualReturnYear10

11.06%

^[9]

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

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rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage based on the lesser of the offering price or net asset value at redemption)

rr_MaximumDeferredSalesChargeOverOther

none

Distribution and/or Shareholder Service (12b-1) Fee

rr_ManagementFeesOverAssets

0.67%

rr_DistributionAndService12b1FeesOverAssets

none

^[4]

rr_OtherExpensesOverAssets

0.38%

rr_ExpensesOverAssets

1.05%

rr_ExpenseExampleYear01

107

rr_ExpenseExampleYear03

334

rr_ExpenseExampleYear05

579

rr_ExpenseExampleYear10

1,283

rr_ExpenseExampleNoRedemptionYear01

107

rr_ExpenseExampleNoRedemptionYear03

334

rr_ExpenseExampleNoRedemptionYear05

579

rr_ExpenseExampleNoRedemptionYear10

$ 1,283

rr_AverageAnnualReturnYear01

12.53%

rr_AverageAnnualReturnYear05

3.02%